A500+ : do I repair the battery damage or build new...

[JezC]

One of the first computers to make this difficult call on is the battery damaged A500+ I got a few years ago (and have had no time to do much beyond remove the battery & neutralise the acid).

I'm pretty sure the PCB has sustained significant damage before the battery was removed, so I'm wondering if I would be better to write that off & just buy a new recreation PCB & build that up.

I've seen a few affordable options here but they're just the bare PCB so I was wondering if any forum members had undertaken one of these builds & had more info on the additional parts required?

I'm pretty sure the custom chips are OK but there are a few others around the battery that probably need to be replaced (possibly including some of the memory) but would welcome the advice.

I think I have seen it boot to a colour screen image & have maybe one game on floppy that it will actually run in its current state, for what that is worth.

So, any polite suggestions/recommendations will be most welcome!

I do have 2 working A500s plus another that needs looking at & a TF536 ready to go into one (and a second TF536 to build up at some point) also.

TIA

[Maximilian]

Just open it up and look, sometimes there is only a little damage and sometimes there's a lot...
It can be quite a challenge if you are not used to repairing electronics and there is a lot of damage.
Make sure you understand that the machine will never be as reliable as a non damaged machine.
(Mine is running strong for a lot of years, but I did an extensive repair)

One option is to buy an A500 with an Rev 8 or 8.1 motherboard and upgrade it to a full A500+, that machine normally does not have a battery because it is delivered without a clock.
Upgrading this unit if you are not used to repairing electronics would also be a big challenge.

Building a machine from scratch can be quite expensive...you need new sockets, caps, resistors and everything that breaks during the harvesting of the old machine.

Post a picture of the damage and we can probably give you some advice, but if you aren't comfortable taking electronics apart I would suggest you send it to someone to be repaired.


Edit: I just saw you already built some remake machines before
In your case I would just try to repair it if the damage doesn't look to bad.
Handy tool:
https://www.amigapcb.org/

[JezC]

Thanks for the swift reply @Maximilian.

Yes, I've built & repaired a few other 8 bit & Atari ST as well as the remake boards but have much less experience with the Amigas to date.

I'll try to dig it out & get a photo or two (sometime this week) to post. It's been a while since I last looked at it in detail and the relatively low price for the bare PCBs was making me think that time-wise it might be a faster build route.

Anyway, I certainly appreciate the suggestions and will go hunting for it soon!

[Steve]

Please see my post on repairing a battery damaged a500+, it might help.

https://exxosforum.co.uk/forum/viewtopi ... =18&t=4698

[JezC]

Please see my post on repairing a battery damaged a500+, it might help.

https://exxosforum.co.uk/forum/viewtopi ... =18&t=4698

Thanks @Steve - I'll give that a read and check the state of my board, though I doubt I'll get as tidy a repair as you've managed there!

[rubber_jonnie]

@JezC I think you already know that we need pictures right?

[JezC]

Yes @rubber_jonnie I'm hoping to dig that poorly Amiga out this evening or tomorrow & then post evidence of the damage.

I have to do it without arousing any suspicion of increasing the collection, so picking the right moment is essential.

[Maximilian]

Looking forward to it.
With the link I provided it should be pretty simple to debug.
(If the damage isn't to bad ofcourse)

[JezC]

Ok, here are some photos of the damage...let's hope the size limit doesn't make them useless!

IMG_20241113_155408869.jpg (378.65 KiB) Viewed 522 times

IMG_20241113_155355930.jpg (438.6 KiB) Viewed 522 times

IMG_20241113_155324889.jpg (427.66 KiB) Viewed 522 times

There's some dodgy-looking green deposits around at least one of the 74 series latches/buffers but probably it's going to need at least that one removing & replacing & bell out for any damaged tracks.

But I'll wait for those with a lot more experience to comment first!

Thanks!

[Maximilian]

This board doesn't look to bad at all.
(but it is a bit difficult to see)

1. Remove socketed chips and check their sockets, pay attention to the Agnus socket and use the right extractor
2. Remove all the corroded parts
3. Remove the lacker from the PCB where the acid has gone.
4. Remove the solder from the affected via's
5. Soak in a vinegar solution
6. Clean with IPA
7. Check traces and repair
8. Add components, fill via's
9. Clean with IPA
10. Test

It should only be a few euro's in parts and if you do it correctly the machine should last a long time.
Take care to order exactly same 74xxx chips or the chips that are listed in the replacement PCB bil.
If you have to replace the internal memory expansion connector then please order one with the longer pins.

Have fun!!