Rev 8A 500+ Motherboard Trace Repair

[reassembler]

Hello!

I was given an A500+ a while back. The battery had leaked badly. I've been slowly trying to get it back to life.

Can someone verify where the trace shown in the attached image goes on the top/parts side of the PCB with a continuity meter? I've highlighted it with a pink rectangle.

The trace goes towards Gary, but I can't find the end-point with my meter - potentially because the track is rotten. Unfortunately I can't find the schematics from this exact revision, so I don't want to make any assumptions before fixing the track. I'm guessing it goes to one of the pins on Gary, but even after pulling the chip from the socket it was all a bit obscured. (And my old man eyes are poor these days!)

Thanks!

[reassembler]

Note, I don't think you'll need the exact same revision of the A500+ to verify this - just an A500+ PCB without track-rot.

[dag]

Use this: https://www.amigapcb.org/

[Cylon]

Amigapcb.org

Dang it, too late...

[reassembler]

Originally Posted by dag

Use this: https://www.amigapcb.org/

Oh wow - that's amazing and gave me the answer straight away!

Edit: and yes, as suspected the track is bad.

[dag]

Originally Posted by reassembler

Oh wow - that's amazing and gave me the answer straight away!

Edit: and yes, as suspected the track is bad.

Yes, great stuff. It helped me too to repair two a500+ motherboards.

[reassembler]

Thank you both. Well I verified the LS244 that I replaced had all the correct connections, found that bad trace.

That being said, DiagRom still flashes green/red (bad chip memory). I'm waiting on a null-modem cable to see what the Serial output says.

I'm not going to shotgun anything - this motherboard is very corroded which makes desoldering from it a nightmare. Not that I'm the best at desoldering, but it's easy to damage pads when the corroded pins are basically one with the PCB.

[dag]

Originally Posted by reassembler

Thank you both. Well I verified the LS244 that I replaced had all the correct connections, found that bad trace.

That being said, DiagRom still flashes green/red (bad chip memory). I'm waiting on a null-modem cable to see what the Serial output says.

I'm not going to shotgun anything - this motherboard is very corroded which makes desoldering from it a nightmare. Not that I'm the best at desoldering, but it's easy to damage pads when the corroded pins are basically one with the PCB.

Try piggyback-ing known good chips over suspicious looking soldered chips just with enough pressure to make a proper contact, and see if it makes change. Also, clean the Gary chip and check its socket too.