Hi thanks for the reply.
Did try a new HDD, worked fine but on reboot off the DVR stopped working again.
I have since got a Hikvision iDS-7208HUHI-K1/4S (second hand) which worked fine with my original cameras so I ordered a new iDS-7208HUHI-M2/P but for some strange reason wont work with my cameras. Both DVR's are set to HD/CVBS the 1st works OK the the latter the footage aint right