Security DVR hard drive Problem

[CCTV Professional]

Hi,
The DVR was performing great until yesterday when started beeping and displaying message "No Hard Drive". After customer restarted DVR all went to normal, but today it happened again.
System shows that no hard drive is present. All the cameras are present and shown on the monitor but no recording. I restated DVR and again all went to normal.
Waiting for your help.
Regards,
Alen

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Answer:

Please do follow 3 things:
1. In DVR menu->SAVE->set DVR to be default.
2. In DVR menu->MANTAINENCE->formate hard drive.
3. Open DVR case to check if the hard drive cables are loose. (Like your computer, move/drop/delivery may cause problem to the hard drive)