Hi,. I'm new here and not at all technical. My Hik Vision system was sounding a system alarm and no longer recording. I switched it off for a couple of hours and it recorded again. After about 12 hours, it alerted again. I thought the hard drive (4tb) might be faulty, as the cameras still function live OK. I replaced the hard drive (a pro computer chum did it for me). An installation engineer reformatted the hard drive, serviced everything and we were OK to go - for about 12 hours. The system runs for about 12 hours before alerting. Switch off for a couple of hours and it runs again. I don't think it's the drive - it's reliable make and new. Do I need to replace the box? Hope someone can tell me what's wrong.