If you still happen to have a MacBook Pro with a dead Radeon 67xx chip, you might be pleased to know there is a fix now. All it takes is an EFI string entered in single-user mode -- which you can often do without video if necessary -- and the 67xx will be disabled, allowing use of the healthy 9400 IGP instead. If you also delete a resistor from the board, the fix is permanent. The only ongoing stipulation is that you must prevent PRAM resets, by password-protecting it to avoid mistakes.
You can go ahead without the resistor delete and only disable the card in the OS to prevent its reinitialization, but one wrong move that reinitializes it will rebrick the laptop -- and there's always the risk of it becoming too inoperable then to even power on correctly
