This is another Icom IC-746 Pro. This unit had a failed backlight in the display, a problem with the automatic antenna tuner, and no audio from the external speaker port.
The backlight problem is fairly common. The pass transistor for the CCFL supply has inadequate heatsinking, and fails eventually. I installed a larger device, and heat sinked it to the CCFL supply enclosure for better cooling.
The tuner was also a common problem. The little stepper motors fail that turn the air variable caps in the tuner. The 746 & 756's use the same motors. I found a source via adafruit for Arduino projects, for the same exact motors. This one got new motors, and was up and running.
Lastly, the lack of audio from the rear ext speaker port was tracked down to a small damaged pc trace at the jack. I bridged the damage, and all was well.
