Amiga 500 Plus with battery damage and an unexpected expansion

I always do what I can to try and help the local community with their Amiga woes and when one local user reached out looking help with his battery damaged Amiga 500 Plus, well I said I'd do what I can.
Not just as bad as some but the battery has spread its contents over a fair bit of the board and there is some damage to repair but that's not the only surprise this machine is hiding. Something called an Vortex AT-ONCE is hiding in the CPU slot and Gary looks like he's made a tower to escape the battery poison.
Featuring the voice talents of @MoreFunMakingIt and @RoseTintedSpectrum. Make sure to check out both their fantastic channels.
CRG Twitter - / yt_crg
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CRG Discord - / discord
Music - Cathode Ray Gun by @Momentvm
Chapters
00:00 Intro
00:36 Lifting the lid
03:53 Testing the chipset and accessories
06:52 Assessing the battery damage
10:26 Inspection after the cleaning
12:10 Removals
13:58 Dealing with the corrosion, breaks and exposed copper
17:23 Trace repair
18:34 Recap A500+
22:21 Recap PSU
23:35 Testing U10, U11, U12, U13
26:28 First test
28:34 Vortex ATonce investigation
32:49 Vortex ATonce testing
37:07 Will it run a game?
39:59 Did it need recapped?
44:01 Conclusion
46:02 Credits
46:51 The silly bit

[@CRG]

Not sure why I tested the low pass filter in my A500+, its got nothing to do with the chipset 😆 and while not shown here, I did soak test the board for a few hours and everything works as it should 😁

[@Adrian_Finn]

Great vid as always, One tip is to cut small sections of solder wick and hold it with tweezers whilst heating with soldering iron. Using solder wick while its still on the roll will soak up loads of heat from the iron and away from the joint.

[@CRG]

Good idea, I'll try that.

[@Adrian_Finn]

@@CRG Learnt this one about a year ago from somewhere and had great success with it, some massive ground planes can still prove a challenge but stand more chance of winning with the technique.

[@weehappypixie]

Fantastic video Glen. The 385v cap in the PSU are typical for switch mode power supplies where the AC voltage is converted to DC. It allows for extra tolerance in the RMS voltage. Give that EU voltages are typically 230V AC + 10 % this would give us 253V AC. Once it goes through a FULL WAVE RECTIFIER 😅 it would give us approx 356V DC. The overhead is built in as some supplies do break the +10% limit especially in the UK. Decent power supplies typically use 400V caps but most cheaper ones for the EU market use the lower 385V ones since the voltage is typical 220V. I've measured 262V AC at home sometimes which used to pop old light bulbs.

[@CRG]

Thanks for the explanation and glad to hear you enjoyed the video 👍. I've seen 245 - 250 at home here but never much above that. 262 does seem a little high. Maybe you're close to the transformer?

[@weehappypixie]

​@@CRGI am close to it. Great work again. Love your videos.

[@kaitlyn__L]

262V! Wow! I'm just down the road from a substation but even so I get only 247V. We used to pop incandescent bulbs all the time in my first home, I'd assumed the wiring was a bit dodgy but maybe the voltage was just a little too high!

[@livefreeprintguns]

I love that you have Audacity running in the background capturing the audio... too much of KZbin is so overproduced nowadays.

[@CRG]

Nothing but the bare minimum here 😂. Seriously though audacity is great at what it does, my microphone isn't the best and it lets me clean up the audio before I bring it into VSDC (the editor I use). I'll admit my entire setup is done on the cheap but I'm just doing these videos for the love of it. A better camera is on the cards though.

[@livefreeprintguns]

@@CRG I love Audacity, been using it for years. I recently started getting into video editing so I use Shotcut for video and if I have to do any post-processing on the audio I simply detach the audio from the video and export it into Audacity... amazing how far open source has come! What camera are you looking at?

[@CRG]

@@livefreeprintguns Still not sure to be honest, been looking at the newer Nikon Coolpix model (I'm using one an older model of it now). Its not the more feature heavy thing but it almost suits me like that, just keep it simple.

[@mikegravgaard340]

I bought a Amiga 500 Plus motherboardoff EBay and my plan is to make a mod for the Amiga 2000 for it. I found you can upgrade the 500+ to 2MB chip, 1MB fast and around 1MB ranger RAM through a trapdoor and Gary adaptor. Interestly I kind of thought this a little odd and wondered how difficult it would be to add this as an option for the Amiga 2000.

[@MrBonesawzall]

Thanks for the video. I've learned a fair bit from watching how you do things using tools that aren't out of reach for us normal folks. I mentioned to you previously that i picked up a mac 128k and an a2000 to restore. You asked for an update so here goes. Mac 128k recap and retrobright complete. Works 95% (problem with the crt vertical circuit). A2000 is up and running, just waiting for upgrades to arrive so I can use it. Had a leaking battery but all the filth on the board seemed to have soaked up the majority of the goo. Thanks again for inspiration!

[@CRG]

The 128k and the A2000 sound amazing. Good luck with the CRT, I unfortunately don't know enough about them to offer any advice, just be careful if you open it up. The 2000EATX has become my favourite Amiga, I'm always using it and with the pistorm it makes a very powerful system. What upgrades did you decide to go for? Happy to hear that my little channel has helped and inspired you to take up the repairs. If I can ever be of any assistance, please don't hesitate to get in touch.

[@MrBonesawzall]

@CRG Thank you, sir. I appreciate the offer of assistance. My list of A2000 mods thus far is an rgb2hdmi with a pi zero, 3.2 ROM update, gotech drive, CR3032 battery mod, and PS2 mouse and keyboard adapters. Next, I'm debating between a terrible fire and a Pi Storm. I like the terrible fire for the IDE interface and non emulated 68k cpu, but I'm not sure how much that matters? What steered you towards the Pi Storm?

[@marillionuk]

I had no idea about cleaning with White Vinegar. I have a few RPC's (6 & 700's) that're suffering with battery leaks and I was tempted to just bin them but after this, they may have another life. The other bit about re-treating with common solder is another boon. Thanks for this and I owe you a pint.

[@CRG]

Just depends on how far gone they are from the battery spill. Any heavy green corrosion won't really lift but it's always worth a try. If you do expose any copper always either treat it with solder or new solder mask or nail polish will also do. Just make sure it works first before you paint it as getting it back off always leaves a mess (speaking from experience) I'll hold you to that pint 😉

[@envoycdx]

Excellent video Glen.

[@CRG]

Thanks, glad you enjoyed it 😀

[@RDJ134]

Watched it picture in picture on the pc while working and posting this video on my dutch website. Great video :)

[@CRG]

I saw it linked, thanks for that, very much appreciated 👍

[@DaveVelociraptor]

When you speed up your face it looks like you're raging and about to burst at someone! Nice work

[@CRG]

Yeah still getting to grips with the picture in picture but thanks, it wasn't so bad this one.

[@JeremyLevi]

I have the upgraded Plus version of the ATOnce for my A500 (main differences are a 14MHz 286, onboard 512KB of dedicated PC RAM, and a 287 FPU socket) and at the time in the early 90s I mostly used it for my highschool homework that required PC software not available on the Amiga like using AutoSketch for PCB layouts for electronics class and running the Turing programming language for CompSci class. You're right in your assumption that games are definitely not what these boards were designed for, the main issue is the emulation of the PCs video card is done in software on the Amiga side and the translation to the Amiga's video output is *very* slow. You definitely want to be using CGA or Hercules mode to get any kind of usable performance out of it and even then it's not really fast enough for action-oriented XT era games. Best you can get is about half the character rate of a stock XT in CGA mode and as you observed there are definitely some compatibility issues as well. You can just about run slow-paced games like the original Space Quest, Gold Box D&D games, etc but even there the slow video output is still pretty noticeable. The EGA and VGA modes are also mono 2-bit modes only so only really good for productivity apps (or running Windows 3.0 if you really want to punish yourself) even if you ignore how much slower they run. Something that does help (a bit) though is if you have some FastRAM in your Amiga as that will be allocated to the board first and does help performance a bit (although the video output still has to talk to CHIP RAM, obviously). Other things not touched on in this video is it does support using more RAM to not only provide the full 640KB for DOS but also 1MB+ memory like any 286 and also supports using the Amiga's mouse (with an included DOS driver), serial, and parallel ports from the PC side of things. HDD drive support can work in two modes, either with a dedicated PC partition / drive or using a hardfile on an Amiga partition. You can also use a RAM/RAD drive if you have enough memory in the Amiga as a small PC boot drive for faster DOS performance.

[@CRG]

Thanks for the info. Since making the video I was able to come to an agreement with the guy who owned it to let me keep the ATonce. I may save it for DOScember but it will appear again and as you say hopefully with some fast ram and maybe a HDD installation it might perform a little better. If anything we'll be able to spend more time with it and hopefully get it setup better.

[@LeftoverBeefcake]

I also have the Plus version, which came as a nice unexpected bonus when I got an A500 off eBay a few years back. Unfortunately I never got around to testing it, since the Amiga itself needed some TLC to get back up and running, and there wasn't much in the way of utility disks for the ATOnce online. Also I have exactly zero PC software to use with it. One of these years I'll throw it back in the machine and give it a proper test.

[@noggin73]

I also had the ATOnce plus (still have it but not the A500!). The hardware was great but the software was crap. Why wasn't the 512Mb available to the Amiga when the emulation wasn't running? (it's real fast ram!). Why was the DOS text mode using 640x200? I wrote my own hacks for this. - A copperlist to stretch the screen to 640x256 (don't think my old A500 was capable of 60Hz but could be wrong) - Add the 512Mb after the ATOnce software started. I've since learnt it's because the ATOnce FPGAs (or whatever they use) are loaded from disk.

[@brooknet]

@@noggin73 512MB?!🐏

[@weepingscorpion8739]

Great video. You were wondering about the Olivetti and Toshiba 3100 video modes. Well, during this time there were many standards about for more capable video modes than CGA. Olivetti had one such in their M24 series of computers and likewise Toshiba's 3100 laptop (pr maybe luggable) also had its own video type. It's interesting that the ATonce can emulate these because these were quite rare. Other such proprietary systems include Amstrad's PC1512 and the Plantronics card which was used in Commodore PC clones. David Murray aka The 8-Bit Guy did a video not that long ago about these Super CGA cards, well worth checking out. I think his game Planet X3 now supports most if not all of these graphics modes, and PETSCII Robots supports Plantronics, IIRC. Fascinating time for sure.

[@Jayoldstuff1]

good video! you got lucky with that one, just one trace repair and some tinning to the other traces, I remember the last A500+ I did. Over a dozen trace repairs removal and replacement of the sockets for Paula Gary FatAgnus and the ROM. and most of the glue logic in the aria replaced. Got it going in the end tho. That was long before replacement PCB's where available, now id probably go that rout with one that bad.

[@CRG]

Yeah it wasn't too bad this one, not as bad as the last one I did as well. Regardless though it is still very satisfying when they come up.

[@jurjanbrust]

Thanks for sharing, I think I learned a lot about fixing the traces watching your video, now need to do it myself and fix the battery damage.

[@oleurgast730]

To clear holes conected to ground or Vcc I normaly just melt the solder and push a medical needle trough. Solder does not adhere to the steel of the needle.

[@CRG]

Would never have thought of that but if it works then why not. I'm sure I could get something from a local chemist.

[@oleurgast730]

@@CRG Actually there are already modified needles to do it more comfortable (they have a handle). Search for "desolder needle". They are available in different sizes, quite cheap.

[@MikeyGRetro]

Great repair job! Glad I’m not the only that struggles with desoldering gun. That vortex card is interesting

[@CRG]

Thanks, I managed to get my solder gun working a bit better after fitting a new tip and new filter. Its still not heating great though and for larger traces needs hot air or another iron to help.

[@Chriva]

That has to be one of the coolest Amiga pc compat mods. No side carts or anything. Awesome! :D

[@CRG]

I was able to work out a deal with the owner to keep the ATonce so we'll come back to it at some point in the future for a closer look. I'm sure with a HDD and some fast ran it'll perform better.

[@ms-ex8em]

u have a great channel - i love it its a good channel as u explain in depth all about different systems thanks.........................

[@miked4377]

nice job crg! its amazing to me that nothing was really wrong with the board after the leakege....cept the one broke trace...

[@CRG]

Yeah it was surprising that the damage was limited to that one trace. Resilient old boards.

[@miked4377]

@@CRG defenitley!

[@MarkTheMorose]

I once (AT-Once?) had a second-hand Vortex PC emulator expansion for the Atari ST, though I never got it to work. I'd actually bought the ST second-hand also, just for Oids, so that was consolation enough. From the looks of things, I didn't miss out on much with the PC emulator, and was very pleased with my first real PC, a Pentium 75 a few years later. (Even that's 30 years ago in 2025. I'm getting too old too fast; I wonder if I can soak myself in vinegar, IPA, and get recapped!)

[@CRG]

GadgetUK has recently come into the Vortex card for the ST and will be looking at it in a video at some point. His is a 386 though. Will be interesting to see how it compares to this 286 card and if it's any more compatible in the ST. I was able to work out a deal with the owner of this system to keep the ATonce, so I will revisit it at some point along with some fast ram and a HDD.

[@josephphillips9243]

Thank you long video but enjoyed it. Your trace repair was interesting. When I see other people do that they do bodge repairs on the bottom. I'm a genuine learner so keen to understand if you chose the solid core wire and your method for reason over the bodge on the bottom? Again thank you :)

[@CRG]

It depends very much on what the damage is. For something like the damage on the 500 in this video its easier to just patch it were its broken against the hole but if it was the middle of the trace somewhere that had broken or if there were multiple breaks in a single trace I'd probably just use a patch wire on the underside. The single core wire is ideal for either solution, I find it easier to work with when compared to stranded wire.

[@josephphillips9243]

@@CRG Thank you for your answer and again for the video.

[@Stefan_Payne]

"this PSU hasn't been used for a couple of days, so I'm confident..." well, sometimes the Cap can retain a charge for days, so its best practice to safely discharge the main cap. You can do that with a large resistor, like a 1k or 10k one and holding it to both pins of the Cap for a couple of seconds...

[@CRG]

I had already checked it and it was discharged but yes always check to be sure.

[@rallyscoot]

ok, so with that resistor voltage drain wouldn't by aggressively?

[@PJBonoVox]

Or just stick a screwdriver across the terminals, as was the way we did it before the Internet.

[@Stefan_Payne]

@@PJBonoVox that would damage the Screwdriver and could damage the cap as well. You don't want a sudden discharge, if you can avoid it, a slower is better.

[@PJBonoVox]

@@Stefan_Payne I've done it for years and neither of those things have proved to be true. Either way he was replacing the caps so it makes no difference.

[@BigThrugg]

That's crazy, when you said the a500+ had an unusual expansion I said to myself, is it an ATonce board. This is the exact config of amiga back in around 91. I wonder what's the chances 2 people here had that config., that is if your friend is here in Belfast.

[@CRG]

Weird coincidence. The machine did come from a local guy just outside Belfast. I've come to an agreement with the owner to hold onto the ATonce so it will be featured again at some point. Hoping to pair it with some fast ram and a hard drive to get the most out of it. Out of interest, what did you use yours for back in the 90s?

[@BigThrugg]

I was at the college of technology in the city center and used the ATonce for some dbase 3 and pascal programming that was taught as part of my course.

[@CompuforceWally]

Hello, thanks for this video. I saw you testing the logic chips with a tester. What is it called please, and does it come with the software application shown here.? Also, why that tester was used, would the logic probe testers not accurate? Or because your have removed them from the motherboard? Never used any of these logic stuff (new to me). TIA!

[@CRG]

Its the TL866+ commonly available from AliExpress and yes its bundled with the software shown. I could have tested them with a logic probe but I had to remove them to properly clean up the corrosion so it was just easier to use the tester. The TL866 is an eprom writer first and foremost but it can also test logic ICs and can test some SRAMs as well.

[@CompuforceWally]

@@CRG Thanks for prompt reply Glenn. Much appreciated :)

[@CRG]

@@CompuforceWally no problem

[@deborahberi3249]

Nice Video! -Mark.

[@Vermilicious]

I thought I saw another potentially bad trace at the corner of C13, between what looks like leg 19 and 20. It's just outside the area of repair. It's hard to tell though. It looked a bit dark.

[@CRG]

A few did look a bit dodgy but tested fine. There are a few dark spots on the solder mask, it's hard to get them all, but the vinegar bath should neutralise the battery gunk and stop it getting any worse.

[@Gunstarrhero1]

did you put some type of lacquer on the solder when you flowed solder over the bare copper? i was kinda yelling at the screen there for a second... nail polish?

[@CRG]

No, I didn't apply any further protection to the solder. The solder is sufficient on its own to protect the copper but yes you can use a further coat of nail polish or solder mask if you like.

[@Gunstarrhero1]

@@CRG wont the solder short? thats why i asked

[@CRG]

@@Gunstarrhero1 Only if something gets in there to short it. I was careful when assembling to be sure there was no shorts plus its only a thin coating of solder. No different really to if something got underneath the board and shorted legs. In hindsight once I new it was working a quick coat of nail polish wouldn't have done any harm.

[@Gunstarrhero1]

@@CRG right, right. i understood that when watching, and i agree, i was just curious if that could happen if it does happen, you know :) thats alot of exposed copper and now solder, besides the point; i know you know what you are doin. good job btw. looking forward to the next.

[@JordNL]

Mesmerized by the Psygnosis video in the back... err what were you saying at the end of the video? 😃

[@nickolasgaspar9660]

finally! someone who lubricates a PLCC chip with contact cleaner before pulling it from its socket!!!!

[@CRG]

It does help and especially when it's corrorded. While it looks instant on the video I did leave it to sit for a while before pulling.

[@kipper2k]

1 thing i found that makes agnus easier to remove is to take the extractor tool apart and use the 2 levers seperately,, it is much better and no slippage

[@ms-ex8em]

the Amiga cover discs from 1992 and 1993 are good - some of them have turbo pascal on them or Amos professional etc !!!

[@retro-futuristicengineer]

This strange socket stack is part of the Vortex AT-Once kit. You could do me a favour if you could measure the resistor and tell me between which pins it sits and which pin is missing. The GARY-Adapter how Vortex called this was missing in my AT-Once Plus kit and I am facing smaller issues like the AT-Once not working with the 1MB RAM expansion card, so would highly appreciate to get information how to rebuild such a GARY-Adapter.

[@CRG]

The resistor in this Gary adapter measures as a 1k 1/4watt resistor. It is installed between pin 48 (5v) and pin 14 (bgack). Pin 14 is disconnected from the Amiga. Hope this helps.

[@retro-futuristicengineer]

@@CRG Perfect thank you. I will get some 48 Pin sockets and this resistor type to recreate this and see if the thing runs better then. By the way I have the AT Once Plus which has a socket for the 68000 (so no more ugly soldering) and a faster 286 - however, this also behaves like "some AT" with very variable speed in Speedsys, the AT Once Plus was actually the very first video I put on my channel

[@retro-futuristicengineer]

@@CRG By the way just looked at some pinouts of the Gary and Pin 48 is not +5V, it is Ground - can you confirm? This would mean holding this permanently low, which, if I understood correctly (Active Low) permanently add the additional waitstate - which would make more sense to me than removing it if some timing-critical things require it.

[@CRG]

@@retro-futuristicengineer Pin 48 of gary is VCC, pin 24 is ground. Checked it on PCB explorer - www.amigapcb.org/

[@falksweden]

I have that card and solved it by bending the leg on Gary out and replaced it in the socket. Added a cable with a resistor and connected to the raised leg and 5v.

[@ms-ex8em]

how does 1 program an Atari st? or Amiga though? would one have to use c+ or pascal etc? thanks...................

[@billcarson9565]

i have got an a500+ and the battery has leaked, can you fix it?

[@CRG]

I'd certainly take a look for you although with what I've got in the current schedule it would be mid to end of September before I'd get the chance. Drop me an e-mail or join the discord if you want to chat about it.

[@rallyscoot]

How strong is the vinegar you are using?

[@CRG]

Just distilled white vinegar, never looked at the strength to be honest.

[@fu1r4]

At 12:20 you add fresh solder and that is great, but why not do that when you use the de-solder iron? You will save a lot of time by doing two things at the same time. That is how i do it and it works for me 🙂 I miss my Amiga 500 Plus 😭 The only thing i have left is the dongle for XCOPY 😁

[@CRG]

There is something wrong with that desoldering station of mine, it doesn't seem to put enough heat into the board to properly flow solder anymore. But yes when it's working properly it's best to apply the new solder with the desoldering gun.

[@Oldsukerbole]

Could you try ahi version 4.18. People always advise this version also with this card.

[@CRG]

The prelude driver I'm using required AHI v6. I should have mentioned that in the video.

[@gvilsan35]

Great video. I have in my A500 that Vortex card and works fine, the only issue I have with this card is Thatcher I don't have the manual in english, the only copy available on Internet is a German version, could you please upload your english version. Thanks in advance.

[@CRG]

No problem, I'll scan it during the week and upload. May as well create images of the disks too.

[@gvilsan35]

@@CRG I would appreciate that copy very much, thanks again in advance

[@CRG]

@@gvilsan35 It'll be Tuesday at the earliest but I'll let you know once I get it done.

[@brynjarborgersen8131]

My main problem with your videos is Ia think they are way to short :lol Strange that, I usually prefer text to read, but I enjoy your videos

[@CRG]

And here's me thinking this one was too long 😄. Happy to hear you enjoyed it.

[@CobraTheSpacePirate]

I got one that goes in the trap door and has and additional 512kB that can be used as slow RAM.

[@Stoobers]

VARTA!!!

[@ms-ex8em]

what about programming ? can u program a pc or Amiga or Atari st? thanks..................

[@CRG]

Can I program? It's been a long time but I did do some of it back in college. Going back 20 years though so it's long forgotten now. I'd love to get back into it at some point but it's hard to find time for everything.

[@SidebandSamurai]

Testing ESR is a little deceptive. It does not show if the cap is leaking

[@CRG]

True and one cap at least did look as if it had started leaking.

[@tenminutetokyo2643]

DOOD!

[@fu1r4]

It would be really great if you could put the text you add to your videos at the top instead of adding it to the bottom of the videos. When you add text at the bottom of the video it will be hidden behind the subtitles/CC. Sometimes you actually do add the text to the top. 😄

[@CRG]

Never thought about the subtitles but noted for future, any on screen text will be at the top👍

[@Trevorodunne]

Leave your voice as normal IT'S FINE GLEN

[@jameslewis2635]

An alternative method I have seen to protecting exposed traces is to use some nail polish which just gets painted on.

[@CRG]

Yep that will work too. The only issue is if you later find another fault it can make a mess taking it off. I've used it before though and like to use clear when I do, shows off the copper underneath 😀

[@plechaim]

I don’t know why people recap 500s the original caps will probably outlive us all on those machines, its only the cheap ones from the 600 1200 and cd32 that need replacing

[@CRG]

Yes it might have been redundant but still doesn't do any harm.

[@Jkauppa]

why would they leave any traces visible, sink them in the pcb completely

[@CRG]

That would mean extra layers and extra cost.

[@Jkauppa]

what window lost focus, press any key

[@Jkauppa]

@@CRG well then, choice of longevity (robustness) or being easily destroyed by a leaky battery

[@Jkauppa]

@@CRG what is recored?

[@Jkauppa]

@@CRG well the cost comes later then if any is allowed to leak