Intel 386SX Upgrade to a TI err Cyrix 486SLC!

[@cosmefulanito5933]

To remove a chip, you have to put it in flux. To clean the pads, you also have to use flux. This way you don't destroy pads as we clearly see in the video. Your work is extremely rudimentary.

Always interesting to see more retro youtubers! Subed so I can see what you do next. Your repair reminds me off two of my Voodoo2 cards I got that was dead. One of the TMU had at leat 1/4 of the pins lose, the other one had one, common issue on those so I did the same, drag solder around with leaded solder and Amtech flux. Did all 3 chips becuse why not, 30 min later I had a fully working Voodoo2, did the next one after I found one lose pin, that one kicked in to life after that to. Oh and yea I picked some ram chips of a donor board to put on a GFX card, just to realize the donor chips had extra 2 pins for separate Vcc for something XD I need to learn to count better lol.

[@DKJones96]

I have to start travelling for work again soon(full time student too) so I'm not sure when my next video will be out but it will likely involve a Voodoo and some soldering as hinted in the end of this video.

@@DKJones96 Yea I wish I had my camera before I repaired my V2 cards. Would have made a nice video. But yea if your planing a V1/V2 repair video that would be super useful to many, most faults on them are relatively easy fixes one you know how to do it, I already fixed all of my V2 cards so out of broken once XD Right now Im working on a Dual Pentium PRO for a friend and making a video about it fixing it up.

[@infinitecanadian]

Most of us probably want to see you repair that board.

[@DKJones96]

I still have it! It's when I'm feeling a bit more ambitious. I have a Voodoo 2 on the table that I'm ready to set aside so I can fix something else for a bit...

[@georgepapa2950]

Lots of practice is still needed, it was painful to watch the first time you are soldering and remove components!!! Reminds me of when i first started in a computer factory repair center 30 years ago.

[@DKJones96]

Got any hints or tips? I've got a few more of these kinds of solder jobs coming soon!

[@MrHBSoftware]

@@DKJones96 he doesnt even know basic through hole soldering...if he knew something he wouldnt have a need for bragging and he would provide tips for you to improve and tell exactly what he thinks you have done wrong. i think you did an awesome job, i would like to see a video about the basic tools one needs to buy to start practising smd work on chips like those, preferrably stuff that can be bought on ebay or similar (worldwide shipping).

[@DKJones96]

@@MrHBSoftware I figured a bit of colon talking was happening when no tips were given. Thanks for the complement, I've been trying to hone my skills so the next video with solder slinging might be even easier than this one was. I've thought about doing a video with basic tools to get someone started. That would be a great informational video that I have everything on hand to do so I will likely give that a go. I've picked up plenty of practice parts and like I said my next video has a lot of this same soldering so it would behoove me to split it into two videos rather than have a 45 minute video of me mostly soldering.

[@someguy872]

What a ride. Sadly that first 486 didn't work. But glad the new one worked! give us some benchmarks or something!

[@DKJones96]

I put a link in the description to the benchmarks, I had benchmarks on this video but trimmed it when it turned out I didn't have the cache enabled like a noob.

[@lordmmx1303]

I have almost subscribed, but there was not a single drop of flux used. FLUX is your friend.

[@DKJones96]

Right on, I've done a lot more of this kind of sobering since this video and definitely use it during desoldering.

[@lordmmx1303]

@@DKJones96 i'm going through your videos and now I'm watching 3dfx mono memory upgrade. Sub is yours.

[@pipschannel1222]

Hi K2, I'm currently working on modding a board very similar to the one in this video. Mine maybe a knockoff of your board. I wondered: Is your board a 2 layer board as well? Mine is, which is of course not ideal for overclocking and such. Boards like these can look the same from a distance.. Mine is very similar to yours and features the exact same components but it's a 2 layered Gemlight GMB-386SAT. Thanks in advance!

[@DKJones96]

It is a 2-layer board. It seems to handle 50MHz without issue. I can't tell you how it handles anything faster but you'll start running into ISA speed issues above that as well. I wouldn't be surprised if there were only a couple different places making these boards as late as they are in the game. That Gemlight does look very similar and I have seen a few others that look similar as well. Maybe a bios chip moved around or something.

[@pipschannel1222]

@@DKJones96 Thanks! The Gemlight may be a rebrand of some kind or the other way around but it's good to know that it can handle 50MHz as I'm going to solder on a SXLC2-50 with a VREG and I'm going to try running that at 0WS using 45ns memory (I just did some shopping @Atheatos ;-) ) My build is going to be a crossover between your two builds. He had the misfortune of having the sleazy SARC/PCChips chipset ;-) I have one of those boards as well but mine even refused to run faster than 30MHz!

[@tahustvedt]

Great stuff. I was surprised to see "486 slc" under the old 386. That loose pad is why you shouldn't drag the solder wick across the pads, but along them. ;)

[@bradsmith8977]

Hey another thing you should do is get rid of the old barrel battery for the bios so it does not ruin the motherboard!!!!!!!

[@DKJones96]

Great advice but that is actually a new NiMH unit! They are green vs the blue that most of the NiCd batteries had.

[@amirpourghoureiyan1637]

@@DKJones96 Most clone boards around that time should have an option for an external battery. If not, then there's a few methods of adapting the barrel battery circuit to accept a non-rechargeable coin cell.

[@big0bad0brad]

NiMH is fine and unlikely to cause corrosion issues. However, more likely for the battery itself to be damaged by the board if the charge rate isn't low enough. Again though, normally that won't cause leakage.

[@clavius5734]

There’s one thing I dont get. First you talk about having blown the processor out because its 3v, and then you talk about the code fetching. How did you figure this out? Did the processor survive in the end, but is simply not running? Or is it more theoretical, like if you would have ran it at 3v it wouldnt have worked anyway? Asking because I’m attempting to do the same 😋

[@DKJones96]

Wow, sorry for the late reply! I'm evidently not getting notifications for them! The processor not trying to fetch code is what led me to believe that the processor was dead. I still have that processor and I haven't messed with it to see if it is actually dead or not but having over-volted it by 50% and the fact that it was ordered on eBay from China it's possible it might have even been dead before I started soldering it to the motherboard. On this motherboard there is no easy way to make the processor see 3.3V instead of 5V. I don't actually know of any 386 board that would allow that and I doubt running the 5V rail at, say, 3.6V to try and split the difference would work but I haven't actually tried that either. An adapter module could be made to regulate down but I am not sure how one would attach that to the motherboard since there is no socket like a DX system.

[@clavius5734]

@@DKJones96 Hey thanks for the reply! Hard to say if your CPU will still live. I wouldn't spend the effort in figuring it out as they're still available and relatively cheap on ebay. I'm happy to report that I managed to get one working :) The route I took was to carefully bend all the 3.3v pins up so that there was 2mm between the pins and the pads. Then I soldered the CPU to the board like you did (thanks for showing me this!). Afterwards I took a single piece of wire which circumvented the whole chip and soldered all the 3.3v pins to that. Finally I took a small 5-3.3V converter, which I connected to a close by 5V point on the motherboard and to the the 'ring' around the processor. And...it worked :) It looks pretty dodgy though. I changed the crystal to a 50Mhz so I could also run the processor at that frequency with the clock-doubling enabled. If you attempt this, do put a heatsink on the CPU, I had issues with it freezing at first.

[@AmstradExin]

I used to have 2 of those....now I'm torn. Either upgrade my 386 Accellerator in my PC98, or the Vortex 386 ib ny Atari MegaSTe........

[@estebanvillalobos2303]

if your pc98 is old enough to have a 386, don't waste your time 'upgrading' it. you'd be better off by getting a 9821 with a real 486. 9801 games run great on a 386 already.

[@Dedubya-]

Would that board accept a cpu socket as it has holes all around the edge of the cpu you're working on

[@DKJones96]

It might? I haven't looked for one. There are sockets for programming microcontrollers that have this layout I just don't know if they make one for a chip with this many pins. I should look into that!

[@dennisp.2147]

@@DKJones96 There's a socket made by AMP that I've seen in Zenith 386SX machines. It allows for easy processor switching. Unfortunately, I don't know the part number.

[@CapNemoDRS]

Flux for desoldering!)

[@DKJones96]

I am going to do that now. I had no idea that was a thing!

[@MRooodddvvv]

Thats looks like a good example why i dont like that solder whick step which pretty much everyone decide to do nowsdays. Why !? Just why ? Whats the point ? Was old solder cursed or somthing ? Can just remove all excess with iron without risquing ripping pads off. Its just looks like a cult of some sort now with some action just "have to be done" without much sence or real use

[@DKJones96]

I usually do it with SMT components so for me it is mostly habit because if you don't the parts never sit flat.

[@MRooodddvvv]

@@DKJones96 i just drag big blob of solder across all pads and it caused even destribution

[@DKJones96]

@@MRooodddvvv I will have to give that a try when I get back home! I've still got a video card that has been de-rammed I can play with.

[@АнтонПетров-д7ф]

+Cyrrix 387.

[@madacpaul]

Hello.can I upgrade the i386sx-20 mhz CPU...to an am386sx-40?are the pin compatible an voltage...thank you.i know it will still work at 20mhz...but will it work?thank tou

[@DKJones96]

You can 'upgrade' to that processor but as you said it'll still only run 20mhz unless you up the bus speed. Is there a particular reason you are looking to make that change?

[@rayer314]

Hi, I tried to do the same thing on one MB where I tried to replace intel 386SX by IBM 33G0275 (probably 386SLC @25 MHz) and it also didn't post. I checked a few different pins but they shouldn't prevent boot (related to cache, PM, etc). The CPU came from a special adapter - 286 to 386 upgrade module. I belive that someone put the module in wrong orientation in 286 PGA socket and blown it all up :( So maybe same story of your TI CPU...

[@DKJones96]

Dang, that's rough. Sucks when someone messes something up like that but we've all been there. The math co-processor on my DX boards make me anxious as heck when installing them because there is no key on the processor or socket to stop it from being inserted incorrectly. Additionally, they like to destroy themselves or the MB when improperly installed. Bothers me that there is no key and that the chips can be destroyed.

[@oldschooldude8370]

Gotta use flux.

[@enilenis]

About to replace my SMD 133MHz 486 chip that has at least double the number of pins. I really hope I don't botch it. I don't even have the special tape for thermal insulation. Only aluminum foil.

[@DKJones96]

You'll notice when I removed the 486 that I burned out from the board that I didn't use the tape. It was more of a pain than a help and just forming the foil around parts to hold it in place does plenty well. Best advice is to make sure you preheat the motherboard. I use an 853A pcb heater. It's not expensive and is available on Amazon even. Pre-heating the board allows you to run lower temps from the heat gun which helps keep you from nuking other parts,, or even the one you are trying to remove. My PCB heater is set to 250 and when I read about 180F on my contactless temperature probe on the chip I want to desolder I fire up the heat gun(an 858D with air set to about 4 and the medium heating tip) at 390 and get to work trying to evenly heat all the pins. I didn't burn anything on the donor board either so the foil might not be necessary but it can't hurt. If possible, try a few junk parts first. That's how I started doing this kind of stuff and maybe soon I'll graduate to some higher dollar boards.

[@moonrisemetasheetdog1603]

nice upgrade! ive upgraded a PHILIPS P3348 386sx 25mhz and a M396F 386sx board with a TI486slc/E -V25PAF. I was suprice about the 3 volt cpu i diddnt know, so i did a quick research about the 486slc datasheets. Since my cpu is a 3volt chip. These cpu's a common used in laptops, according the datasheet: ia800904.us.archive.org/23/items/bitsavers_tiTI486199rReferenceGuide_13259023/1993_TI486_Microprocessor_Reference_Guide.pdf "The TI486SLC/E-V version of the TI486SLC/E offers additional power savings because it operates on a 3-V as well as 5-V power supply." Correct me if im wrong. My lack of knowledge about theTI486slc/E -V low power both systems works witout problems, i just wondering was your Ti486slc indeed 3volt chip or a 5volt? your chip miss the "-V" mark. maybe you may bridge some pins under the chip why it didnt POST? Btw awesome vids :)

[@DKJones96]

I will need to take a look at my part number and see what that datasheet says about it! I was fairly certain that the chip I got was 3.3V only but maybe not? Thanks for the complement! I meant to get a video out for GPUJune to mark the restart of the channel now that my degree is done but that card evidently wants to be showcased next year instead.

[@DKJones96]

Maybe my CPU was just a dud? Being from China who knows what could have been the case but it wasn't trying to do anything when it was installed in the motherboard. I assumed I might have just damaged it but according to the datasheet you linked that should have worked!

[@higamitakaro]

19:30 - is it rebadged or what?

[@LFOSyncToo]

Oh no ripped pad... :(

[@DKJones96]

Yeah, and it would happen on the board I want to keep and on the first processor removal. Fortunately it stayed in place through two removals and installations.

[@LFOSyncToo]

@@DKJones96 Yeah Murphy's law I suppose. Albeit I asked myself why there wasn't flux involved in the removal process? Or am I mistaken?

[@Dedubya-]

@@LFOSyncToo It seems many youtubers love using loads of flux for removal and soldering... I'm not sure you need much or any if using heat to remove a chip like this., you only need to make the solder melt so the pins are released. Flux makes solder flow between pin and pad for a good joint.

[@DKJones96]

@@LFOSyncToo I didn't use flux on removal, should I have? I haven't seen it used before.

[@LFOSyncToo]

@@DKJones96 Yeah you might have. Don't have to use a lot, but on old boards, it makes sense to me I guess. The 'paste' type is better than the no-clean liquidy type for this application. As Dan Wells pointed out, many youtubers do that, even if I think he is refering to Rossmann, the Apple repair guy who use *alot* of flux to remove smd's :-)

[@ryanmalin]

Nice work soldering. I am a pipe fitter by trade. My cousin does all the police radios in the county for a living. All my family has been electricians, hvac/r technicians or truck drivers. Im a huge vr fan. Come join me in vrchat someday!