Oh, i have to correct myself.

I do get CRT heating with the broken logic board, but the high voltage is missing.

I also just tried the reset button, which gives me a nice gong everytime I push it. I also get the usual sad mac sound if I push the NMI button directly after pushing the reset button.

Does anybody have experience with this kind of fault? Could it still be bad caps and the dishwasher trick just didn't do it this time?