PRAM battery. If it's dead, it will not output video. I used to have one of these and a dead PRAM battery prevented the video from being displayed. Also, make sure the CPU card is fully seated (despite being based off the 6400/6500 this used a CPU DaughterCard).
If it doesn't work then, try swapping out RAM modules. Most of them from the 7xxx/8xxx/9xxx series should work. i didn't put a module in mine that didn't work, even 64MB DIMMs. However, 128 will NOT work as those capped. I think that has 3 RAM slots right?
Also, make sure that secondary Riser with the PCI slots is fully seated. That contains the video card for that system. If that doesn't seat, no video.
If it doesn't work then, try swapping out RAM modules. Most of them from the 7xxx/8xxx/9xxx series should work. i didn't put a module in mine that didn't work, even 64MB DIMMs. However, 128 will NOT work as those capped. I think that has 3 RAM slots right?
Also, make sure that secondary Riser with the PCI slots is fully seated. That contains the video card for that system. If that doesn't seat, no video.