Mac Classic - still displaying Checkerboard after full recap

[nullvalue]

I have a Mac Classic that is displaying a checkerboard at startup. Simple fix, right? replace the caps on the logic board.. Well, I did that but it's still displaying the exact same checkerboard pattern. I have a working Mac Classic - swapped this logic board into the working machine to just verify the analog board is OK - same pattern. What else could be wrong with it? do I need to desolder/replace the RAM chips? Can you piggyback test these chips?

 

[GiGaBiTe]

It could be bad RAM, but it could also be logic board damage from leaked caps. If the leaking caps were pretty bad, you may want to try touching up the joints on components around where the capacitors were.

As for the memory, you can't really piggy back SOJ memory chips, you'll just need to replace them.

 

[nullvalue]

There was some crud on the board from the caps but honestly it wasn't that bad - washed right off. No damage to the board from what I could tell..

 

[Timo W.]

Recap the analog board as well (been there - its caps are even worse). Also, clean both boards! The pattern comes not from the bad caps but from the shorts the leaked fluid causes.

 

[nullvalue]

I did run the logic board through the dishwasher - no improvement (after recapping when it still wasn't working). I used a known/working analog board and it still produced the checkerboard pattern so I don't think the problem is anything to do with the analog board.