Sansui 9090 DB Intermittent Stereo FM

[CaseyWKC]

I'm having a very similar issue as this user had previously here - Sansui 9090 Fm Stereo stopped working, Fm Reception OK

Doesn't look like he found a solution and I'm a bit unsure of where to start.

Unit works flawlessly other than stereo reception on FM. It will work anywhere from 10 minutes to 2 hours and then it drops to mono.

19khz vco alignment has been adjusted when the unit was repaired and recapped, and FM alignment was checked as well.

Any ideas?

Thanks all.

EDIT : Thread title was supposed to be Sansui 9090 - Non DB

 

[jefferylhenr]

The mpx ic is failing or afterwards

 

[CaseyWKC]

The mpx ic is failing or afterwards

Should've mentioned I have replaced HA1196 with another I had on hand as I thought it was getting a bit warm to the touch but it seems to have made no change. Will look into the after. Just wasn't necessarily sure what I should be looking for.

 

[CaseyWKC]

I've replaced all capacitors surrounding the HA1196 as well as the IC itself, have replaced TR09, TR10, and TR11 with no change.

The only unusual thing I've noted so far is it looks like on the base of TR08 it looks like I should be getting 12.5v but I am getting 0 - getting the appropriate 3.2v on the collector.