Dometic control board partial failure?

Question: my Dometic refrig is working correctly but recently the lights that indicate what temperature level it's on quit (for the most part). It does light up on level three which seems to be the default setting, but pushing the button to raise or lower the level doesn't light up the appropriate indicator light. Is there a way to test the upper control board to see if it's not working or if it's just not lighting up? TIA