Dell E1705 won't start -- bad video card?

[tmathews]

I'm looking at a Delll E1705 laptop for a friend. When I press the power button I get the power and disk lights to come on for a second or so then go out. Holding the button doesn't help. The battery's built-in charge indicator shows fully charged and the behavior is the same whether on battery, mains, or both. My friend said the machine was working fine then locked up and then when he powered it off and tried to turn it back on this happened.

I pulled the HDD and DVD-ROM but no change in behavior. I disassembled the machine, blew the dust out of the fans and radiators (not too dusty), and pulled the video card. With the keyboard and power button plugged back in the machine would power on and stay on, but without a video card or hard drive I can't tell if it's doing anything. I put the video card back in and got back the on-for-a-second behavior.

My conclusion is the video card has failed but I don't have a spare to swap in to verify this. Before I suggest that he spend $300 on a new video card does anyone have other ideas, preferably with a way to test them? I have a voltmeter and oscilloscope and I'm not afraid to use them if there's something specific to look for.

Thanks for any help.