From Dahua Wiki
Gray screen appears in the IPC.
- Gray screen appears in the IPC, it can recover after restart under the state of power off. Power cycle the device.
- Gray screen appears repeatedly. Check length of the cable run or try different cables. Check POE on switch or NVR. It could be also caused insufficient power supply.
- Check if the IPC power supply mode and power adapter are too far away from the IPC.