Cabin downlights - no power

[UAT Norway]

Both my forward and aft cabin are missing power to the downlights. The ambient lights are working fine, but i can not measure any voltage to the downlights. Any suggestion were to start? Could it be the 301 control panel?

[Yngmar]

Start at the cables, with a voltmeter 

Usually corroded connectors/wires, often at the point where they're crimped to the wire. Rarely it's an actual fuse/switch problem, so work your way back from the lights instead.