RF P200.2 No Sound, not in protect?

[kapnk]

No sound until I back the power supply down to about 11.5V. Then it's faint but changes with the gain. I purchased Perry's manual and have been reading and re-reading the power supply and x94 operations. Some things point towards the transformer. I was also considering the voltage regulators. Nothing looks burnt and no shorts on the outputs but no voltage, either. 26V AC between center legs of Q9 an Q13(right of power terminal). 12.4V DC on the RCA shields. I have some higher than I would expect voltage on TL494 Pin 8, 11, & 12: 24.8V DC. Here are the other DC measurements:

Pin 1: 2.15
Pin 2: 2.45
Pin 3: .0076
Pin 4: .0013
Pin 5: 1.5
Pin 6: 3.4
Pin 7: 0
Pin 8: 24.8
Pin 9: 10
Pin 10: 10
Pin 11: 24.8
Pin 12: 24.8
Pin 13: 5
Pin 14: 5
Pin 15: 5
Pin 16: 0

 

[Perry Babin]

When you post the voltages, do so in one vertical list, like this:


Pin 1:
Pin 2:
Pin 3:
Pin 4:
Pin 5:
Pin 6:
Pin 7:
Pin 8:


What's the DC voltage on all 3 terminals of the LM317?

 

[kapnk]

I apologize for that. I'll make a note.
Pin 1: 24.15
Pin 2: 25.35
Pin 3: 27.0V

So that would be 27 in and 25.35 out according to data sheet?

 

[Perry Babin]

It should be about 13.7v out. Check the programming resistors and their solder connections for this regulator.

 

[kapnk]

R37 is open!

 

[kapnk]

A lot of other resistors are open, as well. I'm going to check them all and make a parts list. I'll report back when I've checked all of them. Thanks again.