Wait a minute, I’m getting fucked here. How did I get two units and not a single plug? Here I’m living on AA batteries and you mofos can plug in to the wall?!?
So without taking my stuff a part - they are pretty specific in their guide that the backlighting is separate from the gauge. So you could have the LED but not anything else.
There’s a decent list of things to check for on the website.
I’m assuming you have one that either connects via USB or has its own power supply. If you are connecting via USB - its possible its your USB and not your gauge. This has happened to me a lot USB ports not being designed to power things all the time…
If you have one that has its own power supply - its probably a connection inside between the CPU and power. You could open it up and take a look or send it for repairs. It could be between the CPU and the display - if you open it up should be pretty obvious with a multimeter where the electricity is not arriving. Of course - might void your warranty… or something like that.
Good luck and please let us all know how it gets fixed. <3