We were sent a replacement Dvr last week and it damaged the card as soon as I plugged in the cameras. Within 15 min. I was looking at recorded video and there were areas where there was motion and it just stopped recording in the middle of people moving in the frame.
The old system in there was an real old DM 16 channel that worked fine for years.
The original cameras that we connected to were Panasonic Box cameras. Most of them are 24 V and dual voltage. They were nice cameras in their day. Still give a pretty good picture.
There were 13 of them powered by two power supplies, one is a 12V and the other is 24V. There was also a transformer on some of the domes that were in the service bays. We put in a Sentry RP Series hybrid Dvr with an i5 motherboard and 2Tb HDD. The original cabling is all coax. The only strange thing is that the power comes out of the two boxes, goes up to the roof and then splits out to about a dozen cameras from there, through 18- 2 cable. We put in Siamese cable when we added 3 runs on the roof and a separate power box with 4 channels that power each camera. We used Cat5 and baluns for the other new runs inside the building and used a 12v 4 channel power supply. The boards were damaged with the old cameras even before we added our new stuff.
Hope this gives you a good idea of what is in there.
Really appreciate your time.