990DB Project Thread

After some late night (for me on the east coast) thread reading I came across a post about the metal shaft of the dolby switch becoming dislodged.

I didn't think a fix could be so simple, but it was! I have both meters and normal audio! I guess I didn't notice when I had it off the dolby board to deal with the pass throughs.

Where/how should I glue the shaft to prevent this from ever happening again?

It still needs some tweaking. But, at least I can play some tunes while I decide whether to tear this thing down and do a full restoration.
I have seen that as well. Had me scratching my head for a bit.
 
Yep I have seen that too, happened to me on my G22000, and my G9000, I had a QRX8001 come in for a input selection fault which was the same thing.

I think the deoxit dissolves or weakens the small dob of glue they put on those shafts.

I put a small amount of Silicon glue/sealant on the shaft, in the inside of the last wafer if I can get to, that solves the issue...
 
After some late night (for me on the east coast) thread reading I came across a post about the metal shaft of the dolby switch becoming dislodged.

I didn't think a fix could be so simple, but it was! I have both meters and normal audio! I guess I didn't notice when I had it off the dolby board to deal with the pass throughs.

Where/how should I glue the shaft to prevent this from ever happening again?

It still needs some tweaking. But, at least I can play some tunes while I decide whether to tear this thing down and do a full restoration.

Interesting! Can you post a picture of the shaft issue?
Thanks for the write up.
 
I put a small amount of Silicon glue/sealant on the shaft, in the inside of the last wafer if I can get to, that solves the issue..

Thanks. That is in my shopping list for my next trip to the hardware store. I don't suppose there is a method to glue the shaft further into the switch?
I will look at some disassembly guides.

Can you post a picture of the shaft issue?

I sure can when I get the dolby board out (for like the 4th time now).
 
Thanks. That is in my shopping list for my next trip to the hardware store. I don't suppose there is a method to glue the shaft further into the switch?
I will look at some disassembly guides.

I do it that way, so its easy to take it apart when you have to remove it and dismantle in the future....only take a little dab, as they say, a little dab will do ya....
 
IMG_20180516_1742536.jpgBefore, you can see how far out the shaft of the switch is (I pulled it out slightly so you could see it better).
IMG_20180516_1743057.jpg Here it is after I pushed it back.

I am having some trouble accessing the shaft to put the silicone on it. I tried using one of my electronics screw drivers to place it in between the last wafer and the black board. I don't know if it will hold. I may have to seek a more permanent solution by putting silicone inside the actual switch knob. Unfortunately I may have to actually take it further apart than I had planned in order to do that....
 
View attachment 1189119Before, you can see how far out the shaft of the switch is (I pulled it out slightly so you could see it better).
View attachment 1189120 Here it is after I pushed it back.

I am having some trouble accessing the shaft to put the silicone on it. I tried using one of my electronics screw drivers to place it in between the last wafer and the black board. I don't know if it will hold. I may have to seek a more permanent solution by putting silicone inside the actual switch knob. Unfortunately I may have to actually take it further apart than I had planned in order to do that....
Yeah the ones I have done were a bit easier to access than that one. She's fully crammed that one!!
 
The one I had. The shaft " clicked" into place securely.

Unfortunately, each time I turn the Dolby knob the shaft backs out just enough to cause audio issues. I will take another crack at it when I do a full recap and relamp.
In the mean time it is getting some play time. Man, does it get loud!
 
Back
Top Bottom