This is what my Power Distribution Panel looks like with the converter module mounted in the bottom compartment. Notice the GREEN board with all the ATC FUSE holder. This is the 12VDC power board. What folks are telling you to check is the 12VDC wires connected to this board with Philips screw connections. Just run a screwdriver down the roll of connections and make sure they are all tight. One may have worked loose causing the flickering or poor non-bright lamp operation. Be careful not to short one connection to another one with your screwdriver.

Just be cautious with the 120VAC side of this panel where the circuit breakers are located. It will be energized if you have shore power connected.
Roy Ken