No video signal when agp graphics card hooked up tp PSU


My problem is that when i connect the 4-pin molex connector to the video card i get no video signal (black screen when computer is turned on). However, when i DON'T connect the molex connector everything seems to be ok. How can this be possible?

MB: Asrock K8upgrade-NF3 (
GPU: Club3D Geforce 6600 256mb AGP (nVidia Corporation NV43 [GeForce 6600] (rev a2))
CPU: AMD Athlon64 3000+
RAM: 1.5GB pc3200 ddr sdram
PSU: 350W

It was previously running on an Epox motherboard until i replaced it but the problem still remained. I also had a Chieftec 450W PSU but it started causing system instability (found memory errors with memtest86+) but switching the PSU made no difference either, The one i'm using now came actually with my computer case (dated way back). I have tried reseating the video card several times, also resetting CMOS and loading bios defaults. Nothing. I pretty much assume that it's some kind of an issue with the video card but can somebody explain how my system can work with the 4-pin molex connector disconnected from the PSU?
4 answers Last reply
More about video signal graphics card hooked
  1. try the video card in another pc if thats not it its your board
  2. Mine has the same error. It stopped sending a signal to the VDU. If I disconnect the power supply molex connector it works again (on a reboot) with the fan still coming on.
  3. Just to make it clear, the molex you're using on the GPU is not a flat inline four pin molex, I believe it should be a 6 or 8 pin power connector. Also Restart it and go into the BIOS and make sure it's set to use the video card and not the on-board video first. Should be set to PCIe/VGA first, then the on-board AGP if no PCIe/AGP detected.
  4. Power down the computer, plug in the video card power, unplug your video cable from the on-board video and plug it into the video card, start the computer making sure the BIOS is set to use the video card first and the on-board video second and hopefully that will solve your problem.
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