9090db Dolby Switch problem?

[smk1969]

A few years back I started a thread about my Sansui 9090db.

http://audiokarma.org/forums/index.php?threads/lightning-damage-to-9090db.437704/page-2

I had it fixed and recapped by an AK member back then. I tried to call him a few times over the past few days, but he has not responded so I suppose he is not interested and I have to find another alternate.

Since it was recapped, it has worked fine and sounded great, but dirty pots developed (sooner than I would have expected) which were annoying. I was always able to regain signal by working the switches.

A few days ago, I was working the Dolby switch - then the sound simply disappeared (there is a very slight sound if I turn the volume all the way up). I am hoping this is not the dreaded Dolby board issue.

I need to find a technician in Des Moines, Kansas City, or even Chicago (I travel there frequently enough). I am guessing this repair is well beyond my abilities. Thanks.

 

[avionic]

Dave (@avionic) is another of the finest in Ft. Dodge.

If I don't recognize a phone number. I don't answer the phone.

I tried to call him a few times over the past few days, but he has not responded so I suppose he is not interested and I have to find another alternate.

 

[smk1969]

If I don't recognize a phone number. I don't answer the phone.

Dave,

It was good talking to you again. I will be in touch soon!

 

[sKiZo]

Try gently turning the switch left and right slowly. If it jumps cleanly to the next stop when it reaches the next click point, it's ok. If it goes intermittent or scratchy before changing to the next click point, it's just the switch. I've not heard of any actual mechanical issues with the switches, so we're talking a good contact cleaning. Those can be kind of a PITA to get to ...

PS - the "dolby board" problem you're referring to is more with the rack of ganged pushbuttons to the right of the meters. Those all run through the same double sided board and you'll drop channels when cycling between those buttons. That's a sure sign that the pass through connections on that board are ready for some TLC ...

 

[LamVu]

I have the same issue. My 9090db has very slight sound at ( dolby fm, play, off, rec-1) position, but it has normal sound at rec-2 position of dolby system.
I did a lot of dioxit, but nothing changed.
Anyone give me an idea.
Thank.

 

[petehall347]

I have the same issue. My 9090db has very slight sound at ( dolby fm, play, off, rec-1) position, but it has normal sound at rec-2 position of dolby system.
I did a lot of dioxit, but nothing changed.
Anyone give me an idea.
Thank.

welcome to AK it is maybe the pass through connections on the pcb .

 

[LamVu]

welcome to AK it is maybe the pass through connections on the pcb .

Which board do you mention here? How do I test the signal througth that pcb.
Thank you.

 

[petehall347]

dolby board is double sided with pass through connections that are prone to go bad . this may or may not be your problem . sorry very late here to think about it . someone else will maybe come along to advise