Today I was using my pc, it was running awfully slow so I restarted and it kept flashing quot;Power cable has not been attached to your video cardquot;. So I turned it off and flicked the master switch on the back of the pc and sure enough it turned on. But it was all low resolution and said no ati driver is installed. I reinstalled all the ATI files and drivers and restarted and the same error message came up. I then flicked the switch on the back and it booted up. I have also checked the Hardware manager and it says for the Graphics card quot;Can not start (error 10)quot;. So what I think is that the pSU is not supplying enough power to the graphics card, so the pc switches to iGP, I have a funny fealing it's the PSU, not the GPU...
It could bet he power supply. The first thing that I would do is to reconnect the power cable that connects to your PCI-Express x16 video card (assuming it uses this slot).
Well, just to be sure, check out this site and examine the capacitors on your motherboard (esp. around the video card slot), on the video card itself, and the ones that you can see inside the PSU. I think that you will find one or more that are bulging...
Assuming you've checked that the power cable to your GPU is still attached? And/or tried different 6-pin plugs into your GPU? If you've tried that and it still does the same, it is likely to be the power supply failing. Only way to rule it out is to try another device, such as GPU, which requires the 6-pin power addition from the PSU - if that works then it's your GPU, if it doesn't work then your original diagnosis was most likely correct.
