Swann NVR8-7085 won't record

Recently picked up 2 Swann SWNVK-870854T-US systems. These consist of NVR8-7085 paired up with 4 NHD-806 cameras. Early this week installed one at my home. Works perfectly. Today installed the other at my parents' home. NVR will not record. Shows an HDD error. On the IP channel menu, the 4 cameras I installed are showing up as Cameras 1, 2, 4, 5, even though they are plugged into POE positions 1-4. And, for whatever reason, in camera 3 position, status shows as "offline". Any advice on what measures to take is appreciated.

Cheers, Greg

Decided to look under the bonnet of the NVR, especially after reading horror stories about Swann support and customer service. Hoping to find something obvious, which I did. Smaller of the 2 wiring harnesses was NOT connected to the HDD. How this was overlooked, I don't know. Quite frustrating on the one hand, but on the other, a big relief that it wasn't something seriously bad. Working fine now. And the step up from my old Defender 600TVL to this 720p IP system is almost staggering, in terms of video quality.

Cheers,

Greg