My friend just got a G5 2.5GHZ Liquid cooled, turns on fine, does the chime and sounds like it's booting up. Except those no video output. I can can confirm it's not the graphics card as I have swapped out it out with a working one from another g5. The only thing now is I get a red led on the motherboard only thing is I can't tell which one it is as it's seated behind the liquid cooling/radiator. It's on the lower half of the board so I would say it's level with lower 1st ram slot.