I drilled some holes in the bottom to let rainwater drain out that could get in through the bearing gaps. My G1000DXC bearing pointer suddenly started moving uncontrollably and then stopped, making further movement impossible. I was able to move it using an external DC 12-20V, but the needle was stuck. Before this, it had issues turning at high speed—first in one direction, then in both. The last time I took the mast down, I saw a lot of water pouring out of the bearing gap. Inside, I found the internal potentiometer damaged, with the positive lead completely corroded and loose. The 500-ohm potentiometer has 5.6VDC across it constantly when the rotor is in standby, so electrolysis can occur if moisture is present. Before opening the rotor, turn it to the middle position opposite the end stop; there’s a mark on the top body indicating the end stop position. This ensures the movable end stop lever will not block at the wrong place. The potentiometer has a 270-degree end...
Ham radio in JO33hg31 53.15N 6.35E