Something damaged my cameras and gpu card.

You can read my old thread:

viewtopic.php?f=2&t=40812

Actually the DVR card was never the problem as I originally thought. After some testing I found out that the cameras stopped working, at the same day my gpu card stopped too (probably at the same minute but I was missing and I can't verify it). I feel that there is a connection between the 2 problems. Is it possible that my PC did something to the cameras? or vice versa that the cameras did something to the PC? Should I just blame the psu of the cameras?

It's a weird situation for sure.

If the camera is placed outdoor, it could be hit by Lightening.

I had 4 brand new cameras. 2 were under a roof and 2 on a stand. Is it possible that the pci card returned electricity to the cameras? I was told this by a person who is involved in cctv installations.

Cameras are connected to PCI cards via BNC cable (signal and ground).

That could be all. No way to drive the current to cameras. But it might happen as long as the cameras and the pci card are connected and the connection to PC would cut off suddenly and no exit to drain out the instantaneous current. The source of current could be electro static by humans or lightening.

Is this less possible to happen when you use a dvr recorder instead of a dvr card on a PC?

Also I noticed that DVR cards have inferior image quality.

You still have chances to break down the cameras and a rather expensive DVR if you switch to the DVR. PC is a lot more robust than a cheap DVR or PC card.

The old PC card could only handle CIF which is a quarter size of D1. So the quality is bad when compared to D1 or 960H's.

I meant image shaking, not resolution.

OK that was me not selecting Pal, when I switched from NTSC to Pal the problem got solved. Now what can I do to ensure there will not be any problem again with burning the cameras (probably from overvoltage)?

Good to know. You saved the card.

I had a 16 channel system fail (all cameras were indoors), it was installed in a Dell poweredge server, by a third party contractor, for a website company that streams video for retail businesses. Looks like the steel panel power supply failed and damaged the card, the video capture card had to be replaced.

Keep an eye on your camera power supply, upon inspection of ours a copper wound coil was burnt, and most of the power supply main filter capacitors were swelled up. The lesson we learned is don't skimp on a low quality camera supply. The replacement supply had larger capacitors, larger heatsinks, and it was caged, versus the old unit which was a bare exposed circuit board.