Kare dvr camera problems

[pablo0874 0]

hello I'm new on here and wondering if anyone can shed some light on a issue I have , I have had a kare dvr with 1tb hdd which I bought last year, the package came with two cameras outdoor and soon after I added another aftermarket one, I have had no problems with three cameras which are all colour with recording or display issues since having it, I decided to fit another camera today on a 30 metre Siamese cable testing the camera on its own was fine and showed on the display, once I connected all four the newest camera showed up as being hd,lcvbs on the display then all the rest of the cameras went off ( blank display ) I tried resetting the dvr , now all cameras are showing blank displays, with a red P covered by a white x on the display , however , the new camera is on it shows lcvbs and is also black and white, there is power at the splitters an power at the cameras, but no displays, I have also discovered that the dvr states underneath that it is a 4 ch ahd dvr, input 12vdc 5000ma , yet the plug supplied states output 12v 4 amps, could this be the problem , I have also tried connecting each camera solely but this does not solve the problem , any input would be useful before I start buying random parts to try to rectify as the cameras are urgently needed, many thanks in advance,