I bought a used head unit as mine had a weak left channel (thanks again Rob).
You can see in the first photo on the left, the case cover was misaligned, I'm not sure what happened, but the keypad wasn't working right either.
I swapped the keypad/display board with the one with the bad channel. At some point, they changed the design, the faceplate is held on with 2 large head screws on the replacement unit, my original units don't have the screws, they are just held on with little tabs.
I had to cut some notches on the board with a dremel to get it to fit in the faceplate that's held to the unit with the 2 large head screws.
The whole job only took about 10 minutes and now I've got a working keypad and the head unit sounds great.
You can see in the first photo on the left, the case cover was misaligned, I'm not sure what happened, but the keypad wasn't working right either.
I swapped the keypad/display board with the one with the bad channel. At some point, they changed the design, the faceplate is held on with 2 large head screws on the replacement unit, my original units don't have the screws, they are just held on with little tabs.
I had to cut some notches on the board with a dremel to get it to fit in the faceplate that's held to the unit with the 2 large head screws.
The whole job only took about 10 minutes and now I've got a working keypad and the head unit sounds great.