Pioneer SX-1250 Dial Lamp Issue

[xXColdShotXx]

I have rebuilt every board in my SX-1250 except the tuner. I have an issue with the 4 main dial lamps going from barely lit dim to kind of bright randomly. Has anyone else had this problem or does anyone know what may be the problem? Thanks.

 

[markthefixer]

AWR-107 FU5 1.5 amps blue transformer wires. pins 12 (out) & 11 (in) - one blue wire transformer winding wires is grounded.

AWX-096 grounded. IF not the fuse, check the wires and connections.

 

[xXColdShotXx]

I've tested the wires going to the 4 bulb rail before and it showed 6 volts or so. Since that purple wire from pin 12 goes to AWM-091 protection circuit board pin 2, would it have anything to do with the popping through the speakers when power is turned on and off?

 

[rcs16]

6VAC seems low for the lamp V.
The wire marked as "A"on the big schematic (~7.5VAC) is used for the AC presence detection on AWM-091.
do you have a bad contact at the fuse holder on AWR-107? or the 1.5 A fuse has issues?, measure the VAC on both sides of the fuse holder, with respect to chassis ground. could try measuring with the fuse (FU5) in & out too.
bad or poor ground connection for the blue transformer secondary wire.
rotate the fuse in the holder, sometimes they oxidize and make bad connections
Good Luck Rick

 

[xXColdShotXx]

I finally figured out the dial lamps issue. The purple wire peg on AWR-107 board was loose.