No image on screen (DVR & NVR)
Hold right mouse button for 8 seconds (till you hear a beep), this will change the resolution.
Repeat up to 4 x until image is displayed.
No online connection via Powerline Adaptor (NVR & DVR)
Connect recorder LAN port directly to the router LAN port.
Login to the recorder, Settings > Network > TCP/IP >Enable "Obtain IP automatically". Once recorder gets its own IP (not 192.168.1.200) then take recorder back to the powerline adaptor and reconnect.
Recorder not online when a new broadband router is fitted. (NVR & DVR)
Login to the recorder, Settings > Network > TCP/IP, untick "Obtain IP automatically" click Apply, then re-tick and click Apply again. This allows the recorder to communicate to the new router.
No camera audio on DVR
Login to the recorder, Main menu > Camera > Camera Signal > Audio Over Coax (enable for each camera requiring audio)
VIPER-5MPL - No audio
VIPER-5MPL2 - Has audio
No image from a Dahua camera on DVR
Login to recorder, Settings > Camera > Camera signal - change signal type for channel to CVI. (If no CVI option, camera needs to be manually changed to TVI using a Dahua DVR or Test Monitor)