adr3naline fix

I bought a 4 channel setup off of ebay. (4 WIRELESS Camera +4CH DVR Security Surveillance System) is the name of the auction since i cant post a link within the first 5 days of membership on this forum I plugged a camera in 20ft away, and then activated the camera in the program...it just brings up a error that says "NO VIDEO SIGNAL". Stays either a black or blue screen I need help baaaaaaadddddd PLLLLLLLLLLLLEASE HELP ME!!!!!

they record stuff

sounds like an ebay model