The tool itself that does the diagnosis is sometimes faulty. Don't fall victim like i did...insist they fix it at their expense, not yours.
The situation resolved itself in a way beneficial to myself buy inconclusive for the purposes of this discussion. The AASP claimed to have resolved the computer's sporadic video anomalies by simply resetting the PRAM. He told me that although its serial number and date of purchase made it eligible for the logic board replacement program, it, in fact, had no GPU issues. I was sceptical because the kinds of distortion and blacking out I had experienced seemed unlikely to be related to the PRAM, but having a written diagnosis from an AASP saying the computer was in good working order, I took it home, and after using it continuously for a month and experiencing no video problems, I sold the computer for $1000.
I am able to verify that the replacement program was extended into a fourth year.
It seems that my logic board in my early 2008 MBP 15 that i bought in Dec 2008 is bad. If I bring in my MBP to an Apple store how are they supposed to run the test for a faulty GPU if the MBP won't even powerup? After I press the power button I head the DVD access and then the MBP shuts off. Won't the "genius" just say the logic board is toast?