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.