This Mac SE/30 was severely damaged and it's my fault

(Note: Extra context in the pinned comment) In a recent SMMC episode, I tested out three of my Mac SE/30 motherboards and found one of them had a strange and worrying fault. In this video I dive deep into what is the problem with this board and see if I can get it working again.
Part 0: • 0089 Troubleshooting M...
Part 1: This part!
Part 2: • Fixing a dead Mac SE/3...
-- Links
Mac SE and SE/30 PicoATX PSU adapter:
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-- Tools
Deoxit D5:
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O-Ring Pick Set: (I use these to lift chips off boards)
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Elenco Electronics LP-560 Logic Probe:
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Hakko FR301 Desoldering Iron:
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Rigol DS1054Z Four Channel Oscilloscope:
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Head Worn Magnifying Goggles / Dual Lens Flip-In Head Magnifier:
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TL866II Plus Chip Tester and EPROM Programmer: (The MiniPro)
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TS100 Soldering Iron:
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EEVBlog 121GW Multimeter:
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DSLogic Basic Logic Analyzer:
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Magnetic Screw Holder:
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Universal ZIP sockets: (clones, used on my ZIF-64 test machine)
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RetroTink 2X Upconverter: (to hook up something like a C64 to HDMI)
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Plato (Clone) Side Cutters: (Order Five)
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Heat Sinks:
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Little squeezy bottles: (available elsewhere too)
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--- Instructional videos
My video on chip removal without damage:
• How to remove chips wi...
--- Music
Intro music and other tracks by:
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@itsnathandivino

[@adriansdigitalbasement]

Note: Patrons and KZbin members already have access to part 2, showing what I do next to understand what's failing. The MLCC caps I installed at 47uf and are not flat, like low value ones. They are square when you look at the end, meaning that rotating them doesn't make them stand up on the PCB, so the best way to install them is to just position them where they don't overlap with traces. Also, after making this video, I stumbled across a diagnostic mode that exists in the Mac ROMs. This was put there by Apple to work in conjunction with their "Tech Step" tool which plugs into the computer's port and allows you to run diagnostics. In part 2, I delve deep into how this all works and how it can be used to fix Macs. Tech Step was a dealer-only tool that is extremely rare and expensive. It has recently been replicated, but the replicas aren't particularly cheap. (They are very cheap compared to the originals) Since Tech Step talks to the Mac over the serial port to perform diagnostics of a machine, that means we should be able to run all the tests manually. I found this archived page which talks about the protocol that is used: web.archive.org/web/20210516085835/mac68k.info/wiki/display/mac68k/Diagnostic+Mode So this is a great lead (thanks to Brian for getting me the latest most up to date version of this page) as this gives us some good insight into what might be failing here! With the info on this page, it will be possible for someone to write some scripts to run on a modern computer to run these diagnostics on a Mac and give you some human readable results... and of course one can just do it by hand.

[@wurst_the_grey]

Interesting article, so does that mean you can get serial output by connecting a specific pin of via1 to ground?

[@adriansdigitalbasement2]

@@wurst_the_grey Seems so -- I haven't tried any of this. I did see on this machine the serial port seems to show some sign of life when the machine crashes. I assume if you get a sad mac you don't even have to force diagnostic mode, I think it goes right into it. (It's my hunch)

[@sonicunleashedfan124]

There are people making replicas of the TechStep

[@perhansson6718]

@@adriansdigitalbasement2 Tony359 shows the replica of a Apple TechStep in his latest channel video, so you can check that out and maybe get ahold of one

[@CayMacVintage]

Adrian, we have the reproduction TechSteps for sale complete with all roms and in a nice printed case. On website it can be found $400.00 each which is a very low price compared to what the originals go and most of this cost is due to the hard to find chips.

[@DarthGylcolious]

Your "what!?!" and face when the voltage spiked off the scale to 12V on the scope was priceless. Thanks for a great vid.

[@snarfusmaximus]

How you do this without dropping f-bombs left right and centre is nothing short of a miracle. You have far more patience than I do.

[@vhfgamer]

The thing is... he probably IS dropping F bombs. He's just not including it in the edit. I edit f bombs out of my videos as best I can because... ya know... youtube.

[@mrcassioo]

@@vhfgamer It would actually be funny hearing the edited *beeps*.

[@Ev1lHaX0r]

The death scream of that CPU was absolutely hilarious.

[@adriansdigitalbasement]

I really did jump from it!

[@Eireman_on_Twitch]

SPOILERS!!! 😂

[@Eireman_on_Twitch]

“Don’t let me go, Mr. Stark!”

[@GalileoAV]

This channel finally got a hardware jumpscare

[@nyccollin]

Why didn’t you timestamp it?

[@elfenmagix8173]

due to it being immediate, the Mac SE/30 is nit seeing RAM. The Mac 68K Initialization routine are as follows: - Turn on the 68K; ROM is connected to the 68K through the PALs/GALs and some logic chip at address $0000-0000. It checks for some basic things (I/O, memory mapping, etc.) The 68K sees the ROM and starts activiating its code at $0000-0000. -Then through some Logic Magic, the system is paused and the ROM is moved to the top of memory $FFFF-FFFF, and the CPU jumps to the new address.in that area. Like on the C64 - When the ROM is shifted out of place, this exposes the RAM, in the Mac's case this is the RAM in $0000-0000. Then the Mac does a RAM Test to see how much RAM is there. Once it counts the RAM, it searches for peripherals for booting the OS. That SE/30 does not seem to go past that point where the ROM is being switched into upper memory and the RAM being exposed and counted. Broken ADdress Trace? Bad Gal/Pal, even though you tested it and it tests "Good"? You many need to unsolder all the chips above the RAM and check for broken traces. In the 68MLA group in fixing Mac SE/30s, this area was known for broken traces when caps spill their goo. At best you have a working Mac SE/30 with broken traces. You can get that replacement Mac SE/30 board somebody is selling and build a new Mac SE/30 from the chips on this board. Horrible thought, isn't it? But it would bring back the soul of the machine into a new logic board. Is it worth it? If I had the money, I would. Just be careful, the 68K Macs are all 4 layer boards. (The PowerPC Board can be 4 or 6 layers depending on the model you are dealing with.).

[@jwhite5008]

Makes sense. I'm commenting to hopefully get more attention to this comment.

[@TechUniversity1]

Can everyone like this comment so he sees it! I want to see this board fixed!!

[@sparcnut]

I suspect another one of the replacement MLCCs near the sound chips has shorted through the soldermask to a bus signal on the top layer, just like the initial D3112V short.

[@jwhite5008]

@@sparcnut Everything is possible here but judging from what @elfenmagix8173 wrote (and others said to similar effect) I'd rather start by looking at data, address and enable lines continuity to at least ROM slot and the furthest RAM slot, as well as enable signals themselves. Perhaps the best place to start is to hook the top address lines and/or select lines to a data logger and trying to see what is accessed last (except sound chip for unhappy chime). A cheap $5 Salae Logic clone goes a long way when the CPU is running code but not quite right.

[@HaveYouTriedGuillotines]

Here's a thought: The GLUE chip is possibly bad, and the memory map isn't being switched properly?

[@nemike42]

To protect parts from melting you should be using kapton tape to cover items that might melt while doing hot air rework. To put on a part like these, you should clean the pads and clean the pins on the part and then tin the pins on the board and then place the chip in place and then use the hot air to "tack" it down, then apply flux around the chip pins and then use the hot air again to reflow the solder, then clean up and your done.

[@c1ph3rpunk]

Put a kapton it? 😂

[@AnnaVannieuwenhuyse]

Yes, exactly! ​@@c1ph3rpunktin foil is fine too, if you prefer 😂

[@siberx4]

Surface mount tips: -Hot air is your friend. I know you use it, but for any J-Lead, no-lead, or ball package, it's all you really should be using for both soldering and desoldering. I solder gull-wing packages with an iron, but I remove everything surface-mount with hot air and attach everything except gull-wing with hot air. -You definitely should pick up a syringe of solder paste. Re-attaching chips is _much_ easier with this stuff, and you absolutely do not need to carefully deposit it on each pad individually the way a stencil does. Simply squirt a thin line along the pads by hand and as long as you don't overdo it, it will "magically" ball up and stick only to the pads and leads, leaving a clean install with no shorts. Can only be done if you're resoldering with hot air instead of a soldering iron, obviously. -Pre-heating the whole board can help a ton when working with reluctant chips. In a pinch I've stuck a board onto my 3D printer's heated bed at 80-100c, but there are dedicated heating mats you can buy to bring the whole board up to temperature. Every 10c you heat the board with is 10c of temperature difference you _don't_ have to provide with your iron or hot air station, so it's a lot faster and easier to bring the whole chip up to a temperature where it will release or solder. -If you're working in tight confines with hot air, it pays to shield the surrounding components with kapton tape. This works surprisingly well to keep everything else from flying off the board, and lets you be more aggressive with temperature and air settings.

[@LeoGitarzysta]

With sensitive plastic connector bodies like that, Kapton tape isn't that helpful Aluminium foil or aluminium tape (or a simple piece of a can cut to size) is much better at dispersing the heat away from the sensitive plastic. Kapton simply doesn't melt and can prevent hot air from reaching some areas, but it doesn't really protect stuff that it's glued on.

[@siberx4]

@@LeoGitarzysta You're not wrong, but in my experience I've found that in practice Kapton is usually sufficient to keep the plastics in good shape despite the fact that it only provides moderate protection. It's much easier to apply, and simply preventing direct airflow from the hot air gun is usually enough to do the trick.

[@strredwolf]

The "This Does Not Compute" channel had a Mac SE/30 board that also had issues... but ended up transplanting it onto a new board... and frame... Look for their "I built a retro Mac from BRAND NEW PARTS". Turns out there's a few diagnostic boards you can get to help diagnose things.

[@74656trekkie]

Saw the same Video just after this video here. Especially the „blinkenlights“ ROM board seems handy to see what‘s happening on the address and data bus.

[@strredwolf]

@@74656trekkie That's what I'm thinking as well. There seems to be a lot more tools for Adrian to use!

[@rager1969]

Yep, I saw that yesterday and wondered if Adrian knew about that diag board and if it would help him. Had it come out a couple of weeks ago, maybe Adran would have delayed his video until getting one.

[@macgeek21]

he had a similar issue but his was due to a fault with making his custom board

[@xgford94]

Snap

[@andreas9238]

actually, PLCCs best are soldered like they are unsoldered; hot air, flux and patience use some leaded solder (the mac is using leaded solder anyways), clean up the footprint with solder wick, clean the chip from residual solder with wick, apply a bit of fresh leaded solder to the plcc footprint, preheat the general area with hot air from a bit further away (150C would be a good point to bring the surface of the board to), apply reworking flux (Edsyn FL-22 or the famous amtech stuff rossman recommends), then go closer with the hot air till you can see the solder getting soft, carefully place the PLCC roughly in the right position (you may want to apply a small amount of flux to the PLCC's underside before that), continue heating till the solder melts, the PLCC will get pulled into position by the solders' surface tension that's how i do it downside; you are applying quite a bit of heat, but so do you when unsoldering them the type of flux is critical it should be pasteous, tacky stuff, do not drown stuff in it, just enough to get the job done low airspeed, roughly 380 to 420C of heat, broad heat, like the hot air station you are using anyways option B which might be easier there exist PLCC sockets that fit exactly onto the original footprint with soldering gaps in the bottom of them, i have non clue if they are still being sold, but you then can solder everything in plain sight with only like one or two pins per side being covered partially

[@Astfgl]

Oof, I recapped my SE/30 board earlier this year with tantalum caps and this so easily could have happened to me too. My SE/30 did have a small break in one of the data lines that I had to fix with a piece of wire, and luckily I was being rather paranoid about accidentally soldering caps to the exposed traces so I used Kapton tape to protect everything. But it had never occurred to me that the capacitor feet themselves might touch the traces, even when the soldering is good. Since then I replaced the Kapton tape with some nail coating and everything turned out alright, but if anything this video serves as a warning that a well-intended and well-executed recapping can still have unforeseen devastating consequences.

[@mar4kl]

Definition of a good day: A fix video from Adrian appears in my feed. Definition of a great day: A fix video from Adrian AND a fix video from Usagi Electric both appear in my feed. You guys are both doing what I used to wish I could do back when I was a teenager, and I just can't get enough of it. Thanks for doing your part to make it a great day!

[@AK-vx4dy]

On This Does Not Compute channel, guy ordered new borads for SE/30. And replanted some parts and have community of people wich know se/30 maybe they can help with diagnose.

[@thewi2kbug]

I recently watched the "This Does Not Compute" video about the Mac built with "new as possible" parts.

[@nysaea]

when I saw the 12 volts on the scope I felt a chill of panic down my spine, oh dear... o_o'

[@frankowalker4662]

Same here.

[@CaptainSouthbird]

Soon as the continuity test went "beep" my heart sunk

[@nysaea]

@@CaptainSouthbird THE BEEP OF DOOM

[@jwhite5008]

Yep, right until that moment I thought the video title may be a bit of an overreaction. Nope. I'm probably going to see it in my nightmares now - the data line scope with nothing on screen. But it was uplifting to hear it didn't drop Adrian's spirits as it probably would have mine. Be well!

[@ossangameclub]

CPU says "After what you did, I'm never talking to you, EVER AGAIN!" Thank you for posting this though, and don't feel bad. Doesn't look like there was any way to visibly tell, and I love that you always post the bad as well as the good.

[@NotHAL9000]

On most Mac II series (including the SE 30) Macs, the speed of the death chime will indicate how serious the fault is- the slower the chime, the “worse” the problem.

[@adriansdigitalbasement]

Heh it's good in concept, but unless someone has mapped chimes to particular failures, it doesn't really help :-)

[@NotHAL9000]

@@adriansdigitalbasementIt might give some clues through the source code of the ROM (if that’s available somehow)- it should show what conditions will lead it to play a slower versus faster chime, etc.

[@sonicunleashedfan124]

This also happens with a certain PowerPC PowerBook, I don’t remember exactly which one

[@charlesjmouse]

Bad luck, I hope you work it out eventually. SMT SOLDERING TIP: If you having trouble reliably soldering a SMT IC might I suggest investing in some solder paste and Kapton tape. 1) Tape around your cleaned / prepared IC pads to protect surrounding components. 2) Apply solder paste to pads - you do not need to be neat! 3) Apply the IC in place on to the pasted pads. 4) Go at it with hot air until the paste changes to solder. 5) Check for shorts - probably none!

[@macgeek21]

i used to see ads for this tool that supposedly helped with smt soldering. of course i can’t remember the name

[@EyeMWing]

My suspicion is that you've fully traced down the D31 damage, and are now chasing a different, unrelated, original problem on the board.

[@jwhite5008]

It's quite surprising anything even survived 12v on the data line, I think math coprocessor at least is likely dead. Whatever was selected (and thus brought out of high-Z state) is likely damaged. However that the *current* problem could easily be original, yes

[@mario-bjornpeikert1572]

Hello Adrian! While watching your video I got an idea: With the working board you were able to recreate the fault state by pushing the NMI-switch right after applying power if I understood correctly. What if the NMI-switch on the broken board is broken or the system falsely senses the switch to be triggered at startup? Wouldn't this cause similar symthoms? Keep up the good work and greetings from Germany!

[@TesseractUnfolded]

I had this thought, too... If you're able to replicate the exact behavior through certain steps on a working board, see if those steps might be happening without your intervention on the Problem board.

[@1967CougarXR7]

I was thinking the same. The reset was bad, the interrupt being right next to it....

[@michellybells8657]

I also was thinking this! I wondered if he bothered to Deoxit the interrupt switch off-camera or not, because I think I would have tried that right away after fixing the reset switch.

[@thomasandrews9355]

He presses the button, usually these buttons short open not closed

[@BenjaminSchollnick]

@@thomasandrews9355 True, but the key word is usually. It's always possible that the button is stuck pressed down, or that some junk got into the switch...

[@DarthGylcolious]

Absolutely one of my favorite videos of late. Just an absolute massacre on this board. Part of me wants you to just dig in, go full metal sunk cost fallacy, because I want to know the death toll.

[@Flashy7]

"there aren't many things connected to the 12V on this board" - you must have meant "by design" :)

[@S95Sedan]

Adrian, if you have enough space around the footprint your best bet is to use PLCC sockets, they are readily available and are much easier to solder by hand. Either by using a curved soldering tip or by cutting out the bottom and putting that back in afterwards. Makes swapping chips also alot easier. When removing PLCC in a tight spot i generally add both kapton tape and over that aluminium foil to obstruct fragile/non-heat resistant components, bit more work but keeps things in pristine condition. If you are going to do more smd things in the future and have the space for it i would highly recommend investing in a stereo microscope (trinoculair if you want to record video on it), prices gone down alot over the years for those on aliexpress. What i run here is a Amszoom 3.5-90x one with a 0.5 reduction objective on the bottom, which gives you around 15-20cm of working space. Eakins is a pretty reasonable brand on there aswell. Even for normal soldering it makes it so much more easier.

[@coreykirkpatrick4392]

@Adeian I want to point out that when you tested the rom card and used deoxit in the last video on Basement 2, you did not actually switch them you actually picked up the working one that you already tested, and not the one you took out of the dead SE/30 at 26:40

[@mikebarushok5361]

It's tricky at first, but easier with practice to solder MLCC surface mounted caps on edge instead of flat. The contact area replacing through hole caps is already limited by the pad size so nothing is lost functionally.

[@insanelydigitalvids]

Just fascinating to watch as you go around the board looking for the culprit. Thanks Adrian!

[@letsdoit7630]

Solder CPLD chips by cleaning the IC pins, making sure they are sitting flat (no pins longer or shorter than the others) put some low melting solder on the PCB pads, place CPLD on the pads and use heated air to melt and suck the IC down on the board. That is how I do it.

[@gordon8657]

Adrian, I do enjoy these newer long format videos but I do miss the shorter ones as well. Just wondering if you've thought about throwing a few shorter videos in the mix every so often! Otherwise love the channel and keep up the good work

[@falksweden]

Putting the ceramic caps on on it's side will give them a better footprint :)

[@nysaea]

why did I not think of that? ._.

[@dave928]

@@nysaea why hasn't anyone? with the exception above, that is...

[@nysaea]

@@dave928 right??? I feel so dumb now :'D

[@theghcu]

One simple test that is probably not the issue is to see if the NMI switch is shorting, thereby simulating a NMI press on startup. I doubt that is your problem, but it should be verified as an easy test before continuing.

[@TheDefpom]

@ 50:00 Kapton tape and metal shields for hot air near other items, also use plenty of flux to help it reflow nicely.

[@DBB-KE5DUO]

Thank you for showing the board failure! ... some things are just too far gone and are not meant to go on in this life! 😢 I wish there were better "dead test" software and hardware for the Macs! 😭

[@tony359]

Im glad my Macintosh is not the only one doing similar things - dead first then chime of death! I’ve borrowed a tech step to try and find out what the problem is. I haven’t tested it yet. Hopefully your community can come up with something that might be helpful for the 68000 machines, that would be cool!

[@briangoldberg4439]

whenever i replace SMD caps with damaged traces underneath, i try to use radial caps with bent legs so they can float above the PCB and I can clearly see any potential shorts. sometimes it's difficult to do that if you have limited space to install the caps, but it usually works

[@KAPTKipper]

My Classic II had the batteries "explode" ate the legs off the VLSI chips. That is my definition of catastrophic

[@DerekWitt]

As catastrophic as the Mac Adrian had that had severe corrosion of the chassis. Even the floppy drive cage got it. Battery went kaboom!

[@pigpenpete]

Mini wave soldering iron tip makes doing pretty much any surface mount IC a doddle. I don't know why I don't see anyone ever using one. It has a little cup on the tip you fill with solder and gives you a little reservior of solder to drag. Weller call it a concave hoof tip

[@jjock3239]

Interesting video, I learned from it. Sad to learn that it was a self induced problem, but who can say that they have never made an inadvertent error like that.

[@PeterW-l5u]

Next time you do recapping with MLCCs on electrolytic footprints you could solder them on the small side, in order to avoid exposing more conductive area to the board as the the old caps would have.

[@CayMacVintage]

Need to use the Blink Ram I provided you last year at VCFmw to see if any work going on with the RAM.

[@Nabraska49]

I liked that you pushed through the frustration.. my language gets a lot more colourful when I get hit with the frustration..

[@jwhite5008]

You said it's trying to access serial port, does it actually output an error code or something? Hook a data logger to top address/select lines and compare with good system. What was selected last? What wasn't? Scope data, address, select lines on RAM chips and see if ALL are the same as on CPU, i.e. no breaks. And, condolences for the dead chips. It happens. It's great to see it didn't discourage you. Thank you!

[@jandjrandr]

Everyone makes mistakes that bite us sometimes. Best to look at the bright side that it makes good content and reminds all of us that no matter how good of a job we do or how experienced we are there is always a risk of unforeseen failure, but we should take it in stride. There is still a possibility that this system can be fixed, and your optimism and tenacity is contagious.

[@CayMacVintage]

One other item I have found and its known, the plastic ROM sockets are known to fail. With the rom in the socket pull it forward and turn on the board. This also happens with the RAM and the blink RAM can help you to see if there is any problem with the ram sockets. Just want to give you issues I have found with over the 50+ I have reloaded and repaired.

[@splatmanhooha4264]

Probably just showing my ignorance but could it be the other 65c22? Seems like the 'hot' one was flowing the 12v through it, making it hot but the other could have gone open-circuit instantly so it wasn't getting hot as, because as the circuit was broken, 12v wasn't flowing through it? I don't really know anything about this sort of thing (probably quite obviously) and it may well be that data line 31 didn't go to the other chip so this is all hyperbole but just thought it was worth thinking about. Anyway, greetings from over the pond and keep up the fascinating channel, as one day this 60 year old may learn what a data line and address line do! 😉😀

[@jwhite5008]

This was my thought as well, although I'm cluesless on how MACs actually work My guess is that the heat is because THIS chip was trying to ground it and the other one didn't That does not mean the INPUTS on any of them are not damaged though And the math coprocessor is likely just as fried as the CPU

[@thejeffchen]

The tip to solder PLCC chips is to use small amount of solder per joint. But you can still drag solder those pins - just remember to use a lot of flux. If there is a bridge inside, just draw it out with a big molten solder blob. A small pencil tip works better than the blade or chisel tip. And DON'T stop using Chipquik. They are good for your chips and boards. Drown all the joints with it, and only set the hot air to 480F to 570F. This will make sure the heat stress is much less than your typical hot air temps. And again, use a lot of flux. Remember to clean it up after removal, because this thing doesn't mix well with normal solder. Last, if you don't want the surrounding to melt, mask with tin foil. Little bits of preps go a long way :)

[@froller]

50:00 I use hot air for both desoldering and soldering PLCCs and SOJs. Just cover plastic parts and electrolytes with the aluminium tape (it is used to seal vents) or kitchen foil. I use 2 layers of foil and additional 1-2 layers of napkin for thermal insulation.

[@moonrock41]

When life gives you lemons make lemonade. When life gives you bad Apples...don't drink the juice. Just make lemonade.

[@poofygoof]

68k doesn't start _executing_ from address 0, it assumes the _vector table_ lives at address 0, and reads the initial stack pointer and program counter from 0x0 and 0x4. The ROM switcharoo allowed the vector table to be moved to RAM so the handlers could be modified at runtime. Later 68ks had a vector base register which allowed the vector table to be relocated at runtime so the external switcharoo logic wasn't needed for that anymore. (it could still be useful for other things like shadow-RAM...)

[@SimonZerafa]

'Deoxit in the Socket' really needs to be a t-shirt slogan! 😊

[@rimmersbryggeri]

Oxit happens

[@rommix0]

That's what she said 😏😏😏😏😏😏😏

[@CaptainSouthbird]

You got my vote!

[@Fred_Raimer]

I bet their sales have doubled since Adrian became popular on KZbin

[@TonyHamlyn]

​@@Fred_RaimerI can't find it! I saw Adrian using it in his vids the past couple of years I have been watching, figured it was a US only product since I can't really get it in Australia. Well by luck I had some work early this year in Honolulu Hawaii, but I went into every hardware store and supermarket store there and no-one has heard of it either, it seems to be a real niche product.

[@nickwallette6201]

Whew, solder mask sure does a lot of heavy lifting. When I design PCBs, I'm always a little cautious about routing signal lines too close to rails. I know it's usually not a real issue (damaged mask here being an edge case) but it just makes me feel better giving them a wide berth.

[@retrozmachine1189]

Still watching, only up to 25:30, but fingers crossed. I had a Star Micronix DMP on the bench that was dead. Lights on, nobody home. A check of the 5v rail showed I think 10v - the regulator had shorted. Pretty much every IC including bog standard 74LS series in the thing used that 5v but I replaced the regulator anyway... and amazingly it came back to life. It might still be fixable without replacing everything connected to that data line.

[@gertk2303]

Thumbs up for the tenacity. Hand (re)soldering PLCC needs lots of flux and after soldering with a small hooked tip (to get between the pin and the pad) I usually reflow with hot air and flux. Afterwards check with a magnifier for shorts and/or open connections. When the pads are not protruding from the side it might be a bit more difficult.

[@awilliams1701]

the old matt bothered me. It had a nasty burn mark on it that looked like a bottle opener. So nope, I'm already good with the new one.

[@CaptainSouthbird]

Listen, just because you missed the Late Night in Adrian's Basement parties... (kidding)

[@imqqmi]

I've done a lot of PLCC (re)soldering with the ReAmiga 1200 project. There were DOA ICs that I had to remove and replace etc. At some point I just replaced all with sockets. With plastic melting stuff chip quick is the stuff to use since hot air will melt it. It just takes a lot of practice and best to do that on a scrap board, not the device of importance. Protect with kapton tape, though even with kapton tape if you hit it with your soldering iron it will still melt. It's helpful to have multiple tips you can swap easily ie the 245 series of hakko or clones. Bent tip, hoof tip with a cup in it (my favorite) and a few chissels and maby a knife style tip. And use lots of AM Tech 559 flux, you can use drag soldering with the hoof type tip. Hold the iron aligned with the pins, the cup at the PCB, and trying different angles to get the solder to flow easily around the pins and take excess solder to the next. Flux really helps this process. Usually you can get it to only bridge the last two pins, then scoop up the solder with the hoof tip a few times. Inspect 5 times :) Invest in a good quality digital microscope, that really helps with inspection, and good light ie a swan bendy neck type light you can bend in the right angle to improve visibility. As a cheap alternative use an microscope/zoom app on your phone or buy a macro lens for your dslr camera. The bent tip is handy for tight spaces as well but may be more challenging when drag soldering. Also consider removing the blocking components as well. Extra work but if you have to go back resoldering time and time again, it's quicker to just make proper room to work in. To clean up low melt solder, I usually use double sided tape to stick the PLCC IC pins upwards on a piece of floor board and go to town with desoldering braid and flux. Drag it across the top and the sides, that should take care of it easily. Hot air may warp the board, thermal shock and cause other damage to the board and the component you're trying to replace, dwell times are limited so if you heat them too long they may get damaged. I think these aren't multi layer boards which can take a lot of heat, two layer boards warp more easily. Since PLCCs are so big it takes a lot of heat and long heat exposure. You can also cheat by soldering on smd PLCC sockets, these are easier to solder than the actual chip, if there's enough room on the PCB. I use bent tip to get into the corners without burning the socket. Knife tip may work as well.

[@wysoft]

Every time I did something like this it was followed by a trail of swearing.. I don't know how you keep your composure lol. Great video

[@ovidiu7290]

Next week part 2 please

[@kaitlyn__L]

I notice when CRG does those PLCC chips for building Amiga accelerators he works under the video microscope at all times, and tends to pre-tin the pads before using a bare soldering-iron on the chip legs to reheat the tinned pads and flow around the legs. Lots of flux in between the pads and chip legs, also.

[@CaptainSouthbird]

15:29 When I heard that dreaded beep, I said "oh boy" seconds before Adrian haha

[@zoid9969]

I'd rather run a mile than try and replace SMD components. One of the capacitors on my Amiga's floppy failed, and fortunately I was able to repair it by replacing it with a normal through-hole part.

[@rommix0]

SMD really are a pain to replace. I've tried replacing a NAND chip that was SMD, and I ended up giving up leaving the device inoperable. Never again.

[@buserror]

For PLCCs, or any desoldering with hot air, you can lay 2 or 3 layers of alu foil on top of the whole area, fit in it and push it all around the components so it's snug, then VERY gently cut a hole JUST around the one you want to rework... once that area is removed, the foil acts as a heatsink for the rest so you can hot air all you like, the remaining heat get dissipated by the foil.

[@twocvbloke]

That heavily distorted "sad mac" sound reminded me of a light-up halloween toy I had in the 90s, I think like a pumpkin or skull shaped thing, push a button on it, it flashed a light inside (incandescent, of course!) and played a sound of "thunder" that was very much like that sad mac sound, strange how we suddenly remember things like that... :P

[@Nf6xNet]

I suggest using Kapton (polyimide) tape to insulate traces around the electrolytic cap pads when replacing them with ceramic caps. You could put a piece of the Kapton tape over the whole cap footprint and then cut out rectangles over the pads with an xacto knife. The Kapton tape will survive the heat from soldering on the new cap.

[@CayMacVintage]

Get the redrawn schematics from online and use the Data/Address line matrix to check those data lines from the ROM socket to the main chips (bottom of the Data line matrix) If any chip does not start up the system will not start.

[@stphinkle]

I wondered if there is an issue with another address or data line, or perhaps an issue with the RAM or ROM lines. I wondered this because at time 37:37, if you notice the CENTER of the screen displayed has a different pattern than the other sides (referring to the gray pattern). Look where the tiny white dots are, and the fact that the center is lighter. I suspect that you are missing one of the lines that deals with the addresses of the center region. It might not be 31. I also noticed that that diode with 31 and was it 23 or something you mentioned (forgot the number), I would check to see if that number has any issues. I suspect that you are getting corrupt data somewhere and investigating what is making the center look different may be a clue to what is damaged. I think if everything goes right, the grey (or every other dot black, then white) should be consistent for the entire screen on boot-up if I remember right.

[@TonyHamlyn]

But wasn't the pattern identical on the good board?

[@Renville80]

I have found sometimes after soldering in a new IC, especially SMT, it helps to let it get back down to room temperature first before applying power.

[@hailmynova]

Did you happen to deoxit the interrupt button? Since the sound was the same on the known good bord perhaps the interrupt stuck closed? Grasping at straws with you lol

[@kefkafloyd]

It wasn't a problem with your board but there can be an issue with only populating the first four slots of RAM with certain amounts of RAM on SE/30s. My SE/30 with 4x16MB SIMMs is unhappy when slots 1-4 are populated with 4x16MB SIMMs but 5-8 empty. I then put 4x256KB in slots 5-8 and it started working. I forget if it brings a Sad Mac or a corrupt screen; I haven't duplicated it in a while. I've only seen it happen with 16MB SIMMs though.

[@slightlyevolved]

26:50, great. You've now released the demons.

[@DerekWitt]

He’s dead, Jim!

[@williefleete]

The 12v on data pins would likely be more of an issue if the pins were outputs, particularly when pulling low, but still an issue when high as there will still be a V diff that can kill output drivers, inputs are usually high Z and may actually be able to handle periods of higher voltage levels

[@LozzTheDev]

Hi Adrian, I assume you're wicking up the old solder (which might be unleaded) and reflowing the pads with decent leaded solder? Decent flux such as Amtech flux (NC-559-V2 / V2-TF) always helps especially with regards to SMD soldering, Kaptan tape is also useful for protecting areas (plastic connectors from being melted) too.

[@gvii]

I got a good laugh from the evil, angry Mac. It was very fitting for the situation, lol.

[@donkeymedic]

SMD chips can either be reworked with hot air or a knife or wide edge solder tip. Point tips can not transfer enough heat to the entire pin. In either case lots of flux with ensure the solder stays where it is supposed to. Flux not helps solder melt, but it helps in ball up to itself. You can see this with BGA chips. Look at some of those videos. Search rework BGA. A chisel edge would probably be the best because it will not only flow the pins, but it was also suck up excess solder.

[@donkeymedic]

Just drag chisel along pins together.

[@Foobar_The_Fat_Penguin]

Maybe in the future it would be better to use through-hole ceramic caps instead of SMDs? You can shape the legs so that they fit on the pads (BTDT). It's not going to look as neat, but you would avoid the problem with the large contact area directly touching the PCB (and any possibly exposed traces).

[@whiskerlesswalrus]

With chipquik it is easy to clean up-you take a Q-Tip with some flux on it -heat the are since it is so low melting then using the flux impregnated Q-tip clean up the molten solder like you would clean flux off a board with Isopropyl alcohol-been using chipquik a very long time and it's main advantage is that it melts at a lower temperature and stay melted for a long time so you can manipulate it easier-it takes a little practice to get the technique down but once you do-it works well

[@cannfoddr]

The this does not compute video has some useful links. A really funky looking diagnostic piggy back rom etc

[@hlsix]

Your comment about buffer chips has to do with the fan-out/fan-in capability of the ICs pins. The spec sheets should have the values. It has to do with the chips' ability to sink or source current (current out (the source) & current in (the sink) requirements for the pins). So, you can hang ICs on a pin until you reach that limit (since the pin can only supply so much current). If you still need to have more things connected to the pin, then you need to use buffer chips on the lines. The buffer chips are generally used for larger fan-in/fan-out capability and are often tri-stated.

[@uki352]

Adrian, please! Buy some Kapton tape to protect the plugs and things around, even you only use the iron. Kapton is not only for managing hot air but also for clumsy soldering techniques or unsteady fingers. No shame, I have shaky hands myself and use Kapton. Then all SMD chips that can be removed by hot air, can also be soldered by hot air, however I also prefer the iron method but use lots of flux and drag the fresh solder around the chip. I use a curved pointy tip for that, what makes dragging tin much easier. Don't use chipquick. It is by far enough to refresh solder with good old leaded solder and then use hot air for removal. Replace electrolytic capacitors (32.000h @ 65°C) with polymere caps (200.000h @ 65°C) and it will be fine for the next 100 years.

[@budgiefish]

Chipqwik has its uses but needs a lot of flux to help it stop going 'pasty' and smearing. For heat protection of nearby parts when using hot air just use some aluminium foil (can get adhesive backed stuff on a tape roll too).

[@LarryRobinsonintothefog]

Remember the Tandy model-2 would blink it's drive select light a certain amount of time based on the problem so maybe the Mac has a simular thing.

[@goltuppen4341]

Sad Adrian. Hope you find the fault soon.

[@jeromewink557]

Blue mat: Adrian has now broken continuity. Or start of a new era.

[@trssho91]

I completely approve of the new anti-static desk mat. I use a very similar (if not the same) blue anti-static mat as my desk mat for my computer desk/soldering station/everything else and I will say I have been impressed with how well its been holding up and its more comfortable than the glass surface under it. In the end it also works really well and smooth with my mouse movement and my keyboard rubber feet stay put as some unexpected perks. I have always favored glass desks for soldering due to easy cleanup with a razor blade, but I will be keeping the desk mat. Plus I have a easy connection for a ground wrist strap in the corner of the mat with dual connections, and I did connect/ground the mat to my server rack right next to it so its properly installed and grounded if I ever decide to start using that part like I should be doing, lol).

[@Stefan_Payne]

Have you tried to use a PLCC Socket, cut off the middle thing and solder that in? THat might help in some cases.

[@rvenden]

Very interesting video. Love your forensic work.

[@TheRealParadigital]

Put the PLCCs back on with hot air. Never had an issue myself and I’m not ad adept as yourself with a normal soldering iron. Just make sure to have a good selection of scrap metal plate to use as heat shields for components that might get damaged due to proximity, oh and kapton tape.

[@lemonherb1]

I wonder if PLCC sockets might be easier to solder in. If you clip off the 'floor' of the PLCC sockets, you should have reasonably easy access to solder the contacts, and you can more easily swap out the chips to test back and forth to see whether or not that chip was bad

[@expertmax32]

You should invest on a stencil kit for PLCC and solder paste. Also, kepton tape to protect components around.

[@MonochromeWench]

Board is in that annoying half working state where CPU can execute code and talk to some other chips without issue, but some unknown random component is not working. The obvious things are working. Data lines and address lines seem good. PGA makes it difficult to directly probe CPU pins on as system like this, because I would try to examine Interrupt and NMI signals to see if there are any spurious interrupts during startup causing the cpu to execute the crash handler and if it were it might help as you could narrow things down to which parts can even generate interrupts.

[@diegoknyte]

I love Chip-Quik at times but ya, gotta learn its mannerisms and gotta clean up the old stuff. Nice is if you can keep the Chip-Quik blobs and use them again where applicable. Sure it'll have some normal solder mixed in over time but can get multiple uses, that stuff isn't super cheap.

[@Vermilicious]

It's hard to tell from the video, but maybe they were a bit sloppy in the design when it came to isolating those 12v paths from the other paths. Of course, the board wasn't designed to accommodate those surface-mount capacitors.

[@frenchshark2000]

Maybe you can solder some SMD PLCC sockets if there is enough room like people do on A1200 and A4000.

[@360alaska6]

When installing those type of caps I lift them slightly when soldering to allow them to float above the board.

[@djdoo]

That was the first CPU I literally heard dying... I felt really gutted when heard that sound, it was sad,that poor thing had an electric shock but still said something while releasing its ghost. Maybe it is a good idea to test MBs before recap of course checking for shorts and then power it on briefly? Don't know if it is not dangerous to do that cause there may be greater dangers waiting to appear immediately. Definitely we should check for shorts after recapping or replacing components on boards, through failures we learn always.. Great video cheers from Greece keep up!

[@hollgo626]

When soldering SMD Components, you absolutely need tu use flux. The solder flows much better when applying heat to the board and the chances that you short something by soldering are minimized.Besides the tap soldering that you use there is the drag soldering and the hot air of course. No matter what, always use flux when soldering smd components. Makes life so much easier...

[@adriansdigitalbasement]

Yep, I had flux on there for soldering and resoldering these chips. MG Chemical rosin flux.

[@pr0engineer873]

Putting some Kapton tape on the components you want to protect from the reflow heat will help protect them from getting damaged during reflow.

[@Dutch-linux]

pre tin the pads... then lots of flux.. place the cip on the pads hot air and the chip should slide in place when the solder melts

[@erickvond6825]

In future projects I would recommend putting the small ceramic caps on their side instead of laying them flat. This reduces the footprint eliminating the issue with shorting nearby traces. As for the ROM package I would recommend watching the video in the following link as it may add some resources and possible leads towards reworking the ROMs and/or replacing them with new and possibly improved versions. kzbin.info/www/bejne/sJSWpIOlprR5fZo

[@adriansdigitalbasement]

These large value MLCC are square along the long axis, so turning them doesn't change their width on the board.

[@AB-Prince]

the fact that the via being removed had no effect on the fail state, that would suggest that the failiure is happening earlier than that. my only guess would be the math coprocessor.

[@rtechlab6254]

Use solder paste, flux, hot plate and heat when re soldering smd. It will make it so easy. Aluminium foil to protect plastic parts

[@ralphj4012]

Perhaps time for a logic state analyser startup comparison with a working board. D14 / D16 etc look to be clamps / protection. Maybe a pre-heater under the board to assist with IC removal / refitting (I have no idea what is underneath).

[@lmiddleman]

The 68000 is big-endian, so it appears data bits D31:24 hold the least-significant byte of a word.

[@jaycee1980]

due to the way the 68k bus cycles work, 8 bit chips are typically wired to the top 8 bits of the databus, rather than the bottom as youd expect. Same is true with 16-bit

[@ukaszrutkowski8368]

The D19 "diodes" are just TVS (transient votage suppresor).