A1200 out of storage not booting, only yellow screen

I've taken my stock A1200 out of storage and tried to have a play with it only to be greeted by a yellow screen that resets back to black every 5s or so.

I've read that it's a CPU error where something goes wrong before the guru screen can be thrown, but that it also means the majority of my system is working according to this (http://eab.abime.net/showpost.php?p=989969&postcount=12).

System setup:
A1200 REV 1D4 (Rev0)
No expansion kits

Things I've tried:
Re-seated everything possible, painstakingly checked every IC leg for connectivity to the board.

I've ordered some caps to replace everything but the voltages at the caps appeared valid so perhaps it's not those.

Does anyone know what the power LED blinking means when greeted by the yellow screen/cpu error? It blinks about 10 times before rebooting. Keyboard caps lock does not do anything on its own and I can press/unpress it to light it up.

Running out of ideas, hopefully the cap replacement will fix it!

[bebek]

Cap replacement will not fix it I am afraid. Do not pay for it before board is repaired unless you do it by yourself

I'll be replacing the caps myself, already replaced most near the supply input, I've done it on my A600 before. What's do you think the fault is?

[Daedalus]

Indeed, as bebek pointed out, capacitors in themselves don't cause this sort of issue, so replacing them won't fix the fault. It is possible however that they have leaked, and the leakage has caused damage to traces on the board.

The power LED blinking is just a guru because the OS itself isn't fully running yet, and doesn't mean much by itself. The yellow screen error could be anything really that affects the address or data buses - I've seen it with bad data bus logic on A500s, which would roughly equate to the Budgie chip on the A1200. Have a good look around that area for shorts, damage due to capacitor leakage or anything else. The damage could also be hidden underneath capacitors or any nearby components, so it might be hard to spot.

[bebek]

Check crystal next to keyboard controller.

Thanks for the suggestions, much appreciated. As expected, I replaced the caps, some were leaky and one isolated trace near the RF unit was corroded but still yellow screen.

I'll take a look around the Budgie chip and check the crystal next to the keyboard controller next. Could bad RAM cause it or at this point has the RAM test "passed", assuming there's no address line fault making the RAM test short circuit and give a false positive.

Fixed it, I replaced the on-board chip RAM with new old stock from eBay!

[liviux76]

Originally Posted by ekuidas

Fixed it, I replaced the on-board chip RAM with new old stock from eBay!

Great!
Thanks for sharing the fix!