The FM/AM tuner sections... I include it in this write-up
for two reasons:
1) there was a problem on the FM board,
2) There was in interesting error discovered on the
schematic for the AM board.
(#1 - problem on the board)
The FM (MPX) board lay buried under the AM board.
Here the AM board has been removed. There is a
Transistor hidden under the wires in the lower right
corner of the board that drives the "Stereo" pilot light.
The pilot lamps were burned out so I did not suspect
any other issues. I replaced the lamps when the front
panel was apart for work. After this unit was completed
I did my voltage checks and discovered the voltage to
the pilot lamp was off. hummm...
Yup... I had to strip off the AM board and lift the FM
board a second time, to get access to change the
Before and after shots of the FM board
You can see how messy the FM board was
underneath (Below)... but it was all cleaned up prior
to reinstalling (right)
#2 - error on the schematic