Soundstream Rubicon 502 Repair Problem

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Been trying to figure out whats wrong with a Rubicon 502 board. The board will not power up, none of the leds will light up, no output. The board doesn't have any burnt marks other than some blackish around the bottoms rectifiers(?). Tested each outer legs to:
330k
467k

Any ideas on where to look. Please describe ideas, still in the learning curve.

Pics of the board and attached the schematic.
Picture001.jpg

Picture002.jpg
 

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Here is a little more detailed info on your troubles, just trying to be helpful...:)

Q68 is a MPSW51A and it supplies the 12 volts to the LM3524 PWM control chip.

Q69 is a MPS8099 and it is the turn on transistor for the amp, thus it gets the 12 turn on through this transistor to the PWM supply.

TS1 and TS2 are temperature switches and they can inhibit turn on if they are dysfunctional...

This info plus what Perry has asked for should get you started on your quest...:)
 
NP any help is welcome.

I didn't have much luck in tracing the out the pins. If I'm right then..

Pin 1: 0.00
Pin 2: 2.74
Pin 6: 3.24
Pin 7: 2.21
Pin 10: 0.00
Pin 14: 0.00
Pin 16: 4.92

I did measure each pin with the amp facing in front of you, top pins from left to right:
4.92, 11.35, 0.00, 11.35, 11.35, 0.00, 0.02, 0.18

Bottom pins from left to right:
.002, 2.74, 0.28, 0.00, 0.00, 3.24, 2.22, 0.00
 
Pin 9 needs to go higher for the IC to produce output. From the input voltages, it appears that something external is pulling it down. Remove and check D18. C57 may be leaking (electrically) which could pull it down.

With D18 out if the circuit, all transistors clamped tightly to the heatsink and a 10 amp fuse in the B+ line, power up the amp. Does it produce rail voltage with D18 out of the circuit?
 
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