Turning a Battery Acid Destroyed Amiga 500 into £1,000!

Is it possible to turn THIS battery acid destroyed Amiga 500 plus into £1000? For charity.

A while ago my friend Paul Universal retro boss gave me a couple of Amiga 500 plusses that were beyond simple and economical repair. And for quite a while they’ve lived in a plastic box in my workshop waiting for attention. Earlier this year, on a visit to the RMC cave, I ran into Rob “Peepo” Taylor of the Board Folk, and we briefly discussed his Amiga 500++ project. I expressed an interest and Rob offered to sell me a board at a super reasonable price.
When he later learned the Amiga I was going to be building on his board would be sold to raise money for charity, Rob sent me an extra board, and then donated the money I’d paid him to the charity I was raising money for! What a nice guy!
This October 19th will be the final day of this year’s charity fundraising for the amazing Befriending Scheme, you can find details in the description, and I would like to build a special machine to sell on that day. I think with the right parts inside and out this computer could raise a serious amount of money, in fact I think it could raise over a thousand pounds. That’s about $1300 US, or about 3 million Australian Dolleroos.
I’ll be using as many parts as I can from the two donor machines, and scrabbling around for the rest in my workshop, and also receiving some pretty spectacular donations along the way.
So let’s get building!
Both these boards are definitely repairable. I’ve seen the likes of GadgetUK Chris and Glen from CRG bring back boards in far worse condition than this. But the idea here is to make something I can sell for a lot of money. And selling a motherboard covered in bodge wires and nail varnish is not going to get the job done.
There are certainly some good parts on here, but I think all of the sockets will be heading to the bin. Many of them are single wipe, which is no good at all, and it doesn’t help that the Gary socket is missing a few teeth. The battery goop managed to get into all areas inside this machine, but the other one isn’t quite as bad, and I’m hopeful I’ll get one working set of components from both of these.
Today I will be using this beautiful purple and gold board. Long time viewers might remember one of the centrepieces of last year’s auctions was a ZX Spectrum with a purple motherboard and a smoked crystal case. Well this purple motherboard thing has started a bit of a trend! It helps that it looks absolutely stunning. And when I show you the case a bit later I think you will be very pleased to see that what we came up with for this build is not only in keeping with the theme started last year, it’s also drop dead gorgeous.

To maximise the amount of profit I can make when we auction this computer I’ll be salvaging as many components as possible. Right down to some of the passives.
These ceramic caps are axial types of all different values. It’s perfectly possible to buy these new, but that would waste precious charity money, so I’m removing them one at a time from the old board, testing them in my component tester, straightening the legs, and then soldering them into the new board. It doesn’t take too long and it really helps that all of the values for all of the components are printed on the silkscreen of the new 500++ boards. I think that’s a lovely touch.
There are a couple around the damaged area that are too far gone, in those cases I took the correct values from elsewhere on the second donor board.
After the caps I need to move onto the resistors. Now resistors are very cheap, and I should have everything I need in my highly organised stash. These are really not worth taking the time to salvage so I quickly work through the list, ticking them off the interactive bill of materials as I go. It’s slow, methodical work, and I enjoyed every minute of it.
After the resistors I worked my way through all the other components I could salvage, including the so-called Vidiot, or “Video Hybrid” board. I’ve heard this can be difficult to salvage and is easily damaged during removal. But I managed to get both of these removed from the two boards without visible damage.
These are filter capacitors. They were fun to remove, burning my fingers on just about every one of them.
Resistor arrays, ferrite beads, and diodes all followed. Which just left a few transistors to solder in place. And that was all of the passive components installed. I next installed sockets. Everywhere. And due to some of the legs being trimmed very short, where I had stock I installed turned pin type sockets. More on that later… Miscellaneous components like pin headers, the coil and crystal were all safely transplanted.
Interestingly this weird diode configuration here is not needed on the new board. Rob fixed the bodge that these were fixing on his revision. So the new diodes could just be installed as originally intended.
And then all of the connectors along the back edge were removed from the better scrap board and installed on the new one. I took some time to polish any metal parts that needed attention. These RCA audio jacks are looking a bit tired. I might swap them out later if I can find some nicer ones, but again, cost is a ruling factor here. I’m also a bit surprised they are both red! Would it have really cost you that much to put a red and white one in here Commodore? Anyway, it’s now looking almost complete and I’m really happy with how it’s coming along.
The donor board is now looking pretty empty! Just the memory and some logic chips near the battery damage. The 244’s already removed from this position were both destroyed by the battery leak. I have dim hopes for these 373’s. Removing one of them reveals tide marks from the corrosive gloop. I popped the 373’s into my lovely Retro Chip Tester Pro.
Here I am testing all of the memory and logic chips. It’s possible to test logic chips in one of the cheap minipro, tl866 type programmers, but I’ve found those can be unreliable.
I’m hoping the retro chip tester pro does a more thorough bout of tests, and while the interface can be a little bit clunky, compared to typing the chip into a search box, you quickly get used to how it works.
I tested the memory off camera and was very disappointed to discover that every single chip was faulty. Which seemed kind of unlikely. How could all of them be faulty? They weren’t fake too were they?!
And then I remembered! Along this side of the retro chip tester pro are some jumpers that need to be set when testing certain types of memory. I’d recently run into this whilst testing some 4164 drams from a commodore 64. Without the right jumper set the tests were unreliable. I’ll probably continue to forget about this and have the same facepalm moment every time it happens. But that’s definitely user error, the tester is brilliant.
With the jumper in place all the RAM tested good. Once I remembered where I’d stored all the custom chips I got those installed.
It looks great, but I’m not 100 percent happy with the sockets. The chips with short legs are not very securely held in place. The worst of them is this clock chip. I can just lift it out of the socket without any pressure at all. I really don’t want these to work their way loose in the post, so I think once this is tested and working I’ll remove all of the turned pin sockets and solder those chips directly to the board.
It’s time to switch it on and hope for an absence of magic smoke. And would you just look at that! It works!
Well that’s not quite the actual sequence of events.
What actually happened was I turned it on with the original 2.04 kickstart installed and it worked great. Then I upgraded the kickstart to a 3.1 version and it refused to boot. I checked everything. Swapped every custom chip on the board with known working ones, examined every solder joint, and in the end asked for help. I had lots of useful suggestions from the more fun making it discord members, link in the description, but the one that solved the problem was the person I really should have asked first. Rob Taylor recreated this board so he really should know a thing or two about it, and when I told him the symptoms he pointed me to a forum which explained the problem. This isn’t a fault in Rob’s design, it’s actually something missing from the original revision 8a motherboards. Possibly others too.
Over here there are a couple of spaces for resistor arrays marked RP106 and RP107. These pullup resistors for some of the address lines are not populated by default. Using the larger eprom for kickstart 3.1 means these address lines are required and so without these resistor packs the computer wont boot kickstart 3.1
I sourced a couple of these 4k7 packs and installed them, turned it on and it worked flawlessly.
It would be easy to stick this in its original case, give it a wipe down and then sell it on for charity. But that would be boring and a bit too easy. So instead…
I asked for some help from my amazing supporters to buy a few items to make these charity computers really special. There are quite a few of these new shiny things to see over the coming weeks, but the first one that I want to show you is this amazing crystal case bought by the group using my Kofi donations page. During this charity event all of the money donated there will be used to fund the builds. You might remember the crystal ZX Spectrum with purple motherboard from last year’s event. Well my friend Fuzzy Lee suggested we should do the same this year. Without spoiling future videos too much, this won’t be the only computer in these auctions with this colour scheme!
I have a few choices to make about what goes inside this machine. And the first is this metal shield. This one here is way beyond cleaning, probably not even painting could bring it back. But the other one isn’t too bad, and I spent a while polishing it to a shine. There are still splotches where corrosion ate into the surface, but it looks pretty decent. I took it along with me to show off at the Amiga Kickstart event in Nottingham earlier this year and there was quite a lot of interest. But a few people suggested the metal shield would be better off gone. And I have to agree. We want to see what’s inside this machine after all.
Ahh yes, the special edition yellow snow keyboard. As you can see here it works perfectly well. All I need to do is restore the colour with a spot of peroxide retrobriting. The sun is out and its ideal weather here in the UK for this. I don’t very often retrobrite things. For my own collection I don’t really mind if it has a bit of patina. But this machine needs to be good looking so I invested in a big tub of 12% food grade peroxide and decided to try the submersion method.
Now these keys were seriously yellowed and I wasn’t expecting miracles. And this is my first time using this method so I was kind of expecting it to go horribly wrong. And if you look at this picture of the keys in their bleach bath you can see there is an issue. The keys are floating. And if you look at some of them they have a pool of liquid on their surface. If left like that there would be a different colour patch at the end. Fortunately I regularly gave them a good stir with a stick, and managed to avoid catastrophe. But there are one or two slight marks that you can see if you look really close. But given that the keys look a million times better I think this is actually a win if you compare the end result to how they looked before. If I get time I might swap these out with a set of keys from one of my own machines if they’re in better condition.
Another conversation I had at Kickstart was with the lovely Chris “Cathers”. You will be hearing more about him in an upcoming episode as he donated something amazing for a very special project. No spoilers! If you want to see the huge list of amazing machines and other smaller items we will be selling for charity on October the 19th keep an eye on this and my second channel as I will be giving regular updates. Chris and I were chatting about the colour scheme of this Amiga, and especially about the keyboard. Most of this discussion was around the keyboard PCB which as you can see is nasty green, which doesn’t really go well with all the rest of the colour scheme. Chris pointed out that Dominik from The Digital Retro Bay (link in the description) had created a new keyboard controller PCB and that he had one on display in the next room in purple. Of course I rushed right over and was soon enquiring about it. Dominik explained he was still working out the wrinkles and it would be available in a couple of weeks.
And it’s now available and would be perfect for this build.
But part 1
I’ve decided I can’t go with this option. It’s a great board, and even includes built in hard drive activity with the original floppy LED doing double duty. But this is a bespoke item and a bit too expensive for the purposes of raising money for charity. I think something like this is for a money no object type of build.
But part 2
Rob Taylor has come to the rescue. It turns out that another thing Rob has recreated is the original PCB from a Mitsumi type Amiga 500 keyboard. And he just so happens to have one in purple! This is a recent development so if Rob manages to send that over in time I will show it at the end of this video. But all I will need to do is move all the components from this green board to the new one. Simple!
But the third. This is a good one though.
While I was talking to Cathers Chris at Kickstart. Ooh a tongue twister.
An idea formed. This grotty metal plate on the keyboard. I really should do something about that. And what I decided to do was paint it. A few coats of grey primer, and then a bunch of coats of gold.
It looks really good, I’m very happy with the finish so far. I need to give it another couple of coats and then a coat or three of clear to protect it. I also went a bit mad and sprayed the case for the floppy drive too. How cool is that with its crystal button!?
This is now looking amazing. But how can we make it better?
Well one of the big donations I recently received for this charity event was an Amiga 500 Terrible Fire TF536 from friend of the channel Colcuz Colin. Colin sent a whole heap of things including an Amiga 600 and Vic20 to sell in the auctions. You can see the unboxing of a frankly obscene amount of goodies over on my second channel, link up there in the corner. Thank you again Colin.
A TF536 is an Amiga 500 accelerator with a Motorola 68030 clocked at 50mhz. Making this a machine I would have personally traded body parts for back in the late 80’s. It also has 64mb of RAM onboard and an IDE hard drive connector. It’s a marvellous addition to this machine and my only problem with it? It’s green. But that’s ok, you can’t have everything can you?
Or can you.
Well no. You can’t, but you can get some of the way there. Another friend of the channel Andi, over at the Hack Build Restore youtube channel, offered to swap his own TF536 with this green one. Andi’s TF536 is black. Which isn’t purple, but it’s also not green and there are enough black things inside this machine that it doesn’t stand out like a hammered thumb.
So let’s put all of these pieces together now and marvel at what a beautiful machine it turned out to be.
And in a few short weeks you will be able to bid on this special Amiga 500 Plus, and a bunch of other machines, and maybe we can see it go for the £1000 estimate I plucked out of the air at the start.
For more details check for links in the description or my website morefunmakingit.co.uk where you can find the latest details.
Also if you would like to make a donation to the Just Giving page you can find a link to that near the top of the description and a pinned comment.
Thank you to everyone that contributed to this project. I hope this raises a huge amount of money for the Befriending Scheme.