The only power comes from the house battery bank via the Victron cable.
You posted that you checked and verified that there is power going to the BVM readout. I assume that means you checked at the end of the Victron cable that plugs into the readout.
If you have not done so already it probably makes sense in that case to check the receptacle on the readout for damage (e.g. bent pins or something).
BVM manual excerpt:
2.3 Common problems
No signs of life on the display
Probably the BMV is not properly wired. The UTP cable should be properly inserted at both ends, the shunt must be connected to the minus pole of the battery, and the positive supply cable should be connected to the plus pole of the battery with the fuse inserted. The temperature sensor (when used) must be connected to the positive pole of the battery bank (one of the two wires of the sensor doubles as the power supply wire).
https://www.victrone...FR-DE-ES-SE.pdf
A follow up thought. If you have the bluetooth dongle can you read the BVM-700 using the Victron app (something wrong with the display but unit is functioning otherwise)?
Edited by ckent323, 10 March 2020 - 12:42 AM.