Front-panel dying

My 2012 KPA-head has developed a problem in the last year. For no apparent reason the entire front-panel goes blank, except for LCD-backlight. Knobs and buttons are non-responsive. Have to pull the plug to reboot.

The unit keeps processing audio and switches performance, slots and effects via the remote. It can also be controlled from RM.

Sometimes it happens within 5 minutes after power-on, but usually the unit has to be left running for a few hours first.

Each time I upgrade firmware the problem goes away for a few weeks, or even months. Overwriting impliers refreshing NVRAM content so this may suggest some sort of NVRAM-failure or possibly battery issue. My use of the KPA varies from daily to weekly so it may also be a battery?

What do you think? Faulty NVRAM, battery or failing front-panel circuit?

I should probably post a follow-up on this after working it out with support. It may be of interest to others with similar problems:

Being out of warranty long ago I ended up taking the KPA apart and found that the small circuitboard holding the main CPU was not seated properly in its socket. It had come partially loose on one side. I took everything apart, cleaned oxidation off connectors, removed all dust and put it back together. I have not had any problems since.

Btw; The job was simple, but it does require an anti-static workplace and the right tools for the job. Static discharge may fry components inside.