A1200 green screen

[dougal]

Bit of an obvious thing to say and I'm sure you have done it, but did you try disconnecting any trap door expansions, external drives etc..?

[dougal]

I can't think how you could check the chip ram. Did you check for any leaking caps, maybe you can see some residue on the board near the caps ?

Other then that I'm stuck, maybe somebody more technical can help you out or else you may have to replace the motherboard. Hope that's not the case.

Good luck