Distortion and Volume drop issues

Okay so I have two issues. I haven't dug into it, even though my back panel has been off for some time now.

The first, and I'm thinking possibly just dirty connections, but with the function switch, mostly on Line-In, when I use say and iPod, sometimes when I go to it, one, or both sides are really low and distorted badly, but if I wiggle the Function switch in that little play it has on the line-in mode, it'll get to where it should be, crystal clear and super loud, sometimes one side clears up first, so i have to wiggle the switch more till they both stay clear. Dirty connection maybe? or something different possibly? The volume/bass/treble/etc. sliders all slide nice and don't distort through their ranges. Only changes with the function switch.

Second... I only really notice with the Radio... but after having the radio on for about two hours, the volume drops of a lot. Only the radio that I've noticed, I don't think I've noticed it with Line-in. And its always about two hours before it drops off. No clue on that, other than I read another post where Norm said poor connectivity on the power switch? But if I turn it off or wiggle it, it's still quite... I'm thinking something may be overheating???

Other than that... Great... I still haven't posted my "Superduper LED mod" install I did last year which turned out great. I love it!!! Flashy but Classy.

Edit: Also, these issues are while plugged into a wall outlet.

1. clean the function selector switch with deoxit.
2. When the radio drops out, use a can of compressed air available at computer or electronics stores, or better still, use can of freeze spray and spray the transistors and diodes etc and sii there is any improvement. If yes its probably the component you sprayed that is overheating. Spray only on the tuner board and don't randomly feel or push on any components unless there is a good reason to because many of the tuner components can change tuner alignment if their position changes or in the case of the copper coils,if their shape gets distorted.

Okay I'll try those. I'll probably just spray an area or two at a time, as opposed to the whole tuner board, to narrow it down... Unless I should just do the whole tuner board to verify that it does in fact have to do with that, then do it again in sections? Any areas on the board should NOT spray?

just spray individual components one at a time and observe for improved. Don't spray the transformer or tuning capacitor.

Okay thank you once again!!! Hopefully I'll get a chance to go get some freeze spray and maybe also a can of just air. I'll post what I come up with.

Well, I used the deoxit on the function switch, seems to be working good so far! I tried it months ago, but I must not have hit the right spot, didn't get it good enough. Seems to work perfectly fine after this time using it.

For some reason the last two days I tried running the radio for hours... wouldn't cut and drop the volume... I'm happy with that but confused why it didn't drop at all. Could a dirty function switch maybe have been causing something on the tuner board to overheat? Seems like a possibility, either way, as long as it's working now, I'll be happy with it. I'm gonna keep an ear on it though. .

Interesting. I bet the dirty function switch was the culprit for both issues & was going to suggest that as a possible reason for both....I bet the radio connection across the switch was heating slightly due to a partial connection across the switch in the radio position & after a while would increase in resistance, due to slight heat buildup.....just a hypothesis....

Cpl

The function switch is the first thing I spray after I open the case. It needs it every time.


Glad to hear it is working better.

blu_fuz said:

The function switch is the first thing I spray after I open the case. It needs it every time.


Glad to hear it is working better.

Click to expand...

Yea I'm happy, was afraid I'd have tear into it deeper and replace some stuff. I'll definitely be paying attention to cleaning my stuff better when I notice anything odd again.

I find on some of the more grimier boxes that a couple of passes with the Deoxit/Servisol are required over time to really clean things up ... plus a good repetitive movement of the fader/control for a good few reps after cleaning to really work it through it.

The thing with these 30+ year old boxes is that what works for one is sometimes different for another, as they have all seen different usage patterns over time.

Glad you fixed yours though - these are nice boxes