Equill, I couldn't thank you more. Just when I learned I wouldn't be getting a new logic board, I tried your instructions again and Presto! Worked like a charm. So today it wouldn't start again, but I've learned something - If I want to use my CC any given day, I need to take out the motherboard, hold down the CUDA button for a minuite and then plug it in, flip the switch. Sometime in the next hour, if I keep hitting soft power it seems to always work - sometimes 5 minuites after, sometimes an hour. Perhaps it will surprise me Tommie and break this rule, who knows?

So I'm wondering, if this CUDA button really is the fixing catalyst (and of course it may just be obscuring something else), what does that mean in terms of the issue? Something I can fix?