I installed a new video card, have the unit connected to a Apple 17 lcd that I needed to buy a $99 adapter for to change it to a DVI connection. I have also a 17 lcd that is VGA was used on my pc and works fine. Both monitors have been hooked to my PC and they function. I also have two other PCI video cards that I have tried. All cards and all monitors have the same result, Apple Classic chime when powered on but no video. I am a pc technician and this is my first Mac I have owned. I wanted to learn how to navigate through the OS so I purchased a machine off ebay. I really need to get this unit working any help would be appreciated. I have reseted all connections and ram. Used different ram modules and configurations. E6300 OC'D, 4GB Ram, 8800GTX, Liquid Cooled, Dual SATA DVDRW DL in a thermaltake case

Have to ask, but are the video cards Mac specific?

Yes all cards are Mac specific one is a Rage 128 and the other two are ATI Mac version video cards with 128mb ram. I was also told to reset the pram but the keyboard I have is not a Mac keyboard so I dont know if I can still reset the pram. E6300 OC'D, 4GB Ram, 8800GTX, Liquid Cooled, Dual SATA DVDRW DL in a thermaltake case

Try reseting the Cuda/PMU. http://docs.info.apple.com/article....

I reset the CUDA and also once that didnt work pulled the battery out and let it sit for 2hrs before pluggin it back in. Still no video, I doubt the mobo or processor is bad because the unit make the chimes and all lights come on for the hd, tape drive and scsi card so everything is receiving power. E6300 OC'D, 4GB Ram, 8800GTX, Liquid Cooled, Dual SATA DVDRW DL in a thermaltake case

its a G4 dont know if that matters at all E6300 OC'D, 4GB Ram, 8800GTX, Liquid Cooled, Dual SATA DVDRW DL in a thermaltake case

Does the monitor ever receive power, power light comes on but quickly changes to orange? Will it boot into safe mode (shift key on start-up), single user mode (s on startup) or boot from an install CD/DVD? Check the PRAM battery, it should read between 3.3 and 3.7. Has the machine ever worked since you got it, or has it been a no-go from the start?