Do I have a bad GPU? Strange issue...

I have a 2007 MBP model A1226. I think I have a bad GPU. Here's my situation:

- No chime on startup, black screen. Hard drive spins, but thats ALL that happens. No lit keyboard, nothing.

- When I reset the PRAM, I get a chime, and the keyboard lights up. I can adjust volume up and down. But thats it. Still a black screen.

I tried connecting an external monitor, but no luck. Though I'm not sure how to tell the MacBook to use the external monitor. Should it just automatically detect and start to use the external monitor? I've tried hitting F7 but no luck either.

Is this most likely a bad GPU? Any other things I can try?

Thanks!

Sounds like it. Your model includes the nvidia 8600M graphics card. Take it to an Apple Store, they may fix it (for free). If not, cut your losses, its cheaper to buy a new one than to replace it.