Intermittent Colombus RNS 510 issues

Morning All, thus may have been covered but i could not see anything directly related. My unit will not power on at random times under no certain conditions. The audio can still be heard from the reverse sensor. I have Delphi software and after scanning I seen intermittent faults relating to undervotlage. I have checked over the battery with a multimeter before starting the car and while running with voltage on both accounts more than 12v. Has anybody any insight into the issue before I remove the unit and check connections at the back of the unit?

Many thanks