Help with A500+ does not boot, white screen, blinking power led

[amigo-mexicano]

Hi, I have a cool A500+ for repair, when receiving it, was going guru all the time, no matter what I loaded. It stays OK on boot screen for hours.

It had a previous repair of battery leak.

After inspecting a little, saw some green goo near U12 and C12, so I removed them and cleaned all, tested continuity etc.., but when putting everything back, now I get a white screen and the power led blinks, no boot anymore.

I tested Gary chip on other miggy and works OK. I replaced U12 and C12, and problem is the same.

Any ideas on what to try next?

Thanks!

[Zippy Zapp]

Hi.

Is there anything plugged into the trap door expansion?

I had one that was white screen and if I remember correctly the rom chip needed to be reseated. You might check the chips to make sure they are all seated properly.

I think you may want to try unplugging keyboard make sure it is not bad, seems I remember a problem there too on my old one. This was 20 years ago, though...

[amigo-mexicano]

Hi!

Nothing connected on the trap door.

I tested with and without keyboard, in fact with the bare motherboard, and white screen all the same.

I will re-check all other chips, just to be sure.

Thanks!

[Viserion]

Have you looked at the resistors?

I had a burned resistor at R309 that caused white screen. After I replaced it,it booted up, although it still not as stable as it should be.

[Yulquen74]

have you checked the gary socket? if the legs of the gary chip have turned green, they should be cleaned with a nylon brush or similar.

also, since you replaced some parts, are you 100% sure you did not break any traces/vias in the process? I woud check all traces going to/from the "green" area.

sometimes even vias occasionally fail due to coorrosion damage.

[rikbliz]

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