Distorted Receive on NorthStar 990v

[Mr.715]

Okay so here we go this is quiet odd. Here are test voltages for IC1 starting from pin 1.

0v
3.1v
1.53v
0v
0.25v
0.31v
0.68v
0v
0v
0v
8.67v
1.81v
1.81v
5.9v

These are without a signal injected.

 

[Mr.715]

Possible fault with the Audio IC itself which is causing the distortion on Receive? This is in PA function.

 

[Mr.715]

So hopefully final posting on the thread here. I pulled the Toshiba Audio IC. Dropped in a replacement tested the PA function and it was crystal clear with no faults. Moved to RX and the receive was restored back to excellent with no issues. Seems breakdown/leakage of the audio IC itself was the fault. All in all I'm very happy to get it back rolling and to use it. Now just for an alignment thank you to everyone that got involved.

 

[Cable Guy]

Glad you got it going, I was leaning toward the IC fault but like to verify before replacing. You should still replace all the 10 volt caps however while you're in it. Good job.

 

[nomadradio]

Rock on! Gotta love it when a plan comes together.

73