Cobra 2000 Audio Help Air Blowing Sound Through Speaker

[HavaV10]

Got a old Cobra 2000 GTL late 1978 model. Been fully electrolytic recapped. It has a low air blowing sound coming through the speaker when the volume is turned all the way down. I attached a video explaining this issue with it. The sound is still there even with squelch turned up and rf gain fully counterclockwise. The 2000 used to have a roger beep board in it. I removed that and corrected the wiring to the mic jack but maybe I have the wiring wrong cause this problem. It used to receive with the mic unplugged. Thanks for any help or suggestions.

Mike

 

[VMC]

Transistor junction noise post volume control?
Lot of high-beta Japanese transistors go noisy with age.

 

[nomadradio]

I start by unsoldering the center leg of TR43. If you hear no change, the culprit is an early-production TA7222P, probably a "P" and not the later "AP" version. Can't see that ID on the chip until it's removed anyway. If this kills the noise, replacing TR43 is the next thing to try.

This symptom seems to come up mostly in pre-1980 radios.

73