Intermittent "scratch" noise in left channel (2215b)

drabina

drabina

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I have 2215b receiver that I am looking to restore (recap, LED conversion and cleaning). Now, before I start working on it, I would like to know if the problem the receiver is experiencing is something fixable.

When I listen to it for a longer period of time, one channel (left) gets all scratchy from time to time. The noise is sort of like you would disconnect speaker cable from the post and just touch the post holding speaker wire in your hand. Not permanent connection would result in "scratchy" sound. I can hear that thru speakers and thru wireless headphones (connected to TAPE OUT). I hope you can understand my explanation.

Is is something that recapping and/or cleaning would fix? I do not really want to pour money into it if it not fixable.

Thanks.
 
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Might be just a little cleaning of the controls and switches. There are plenty of threads here on that, & it's not an unusual symptom to be coming from a gunked up volume or balance control, or the tape monitor switch.

Try also switching your inputs left for right to verify that it's the receiver as the cause.

There's a sticky under General Audio Discussion that describes using DeOxit:

http://www.audiokarma.org/forums/showthread.php?t=207005
 
I had this issue with a 2250. Not only did I get the "pops," one of the channels would fade out and I would have to tap the receiver to get it to come back.

Cleaning the protection relay fixed it and it was very easy. It's the relay that "clicks" shortly after you turn on the power. It's pretty easy to do. To find it, lift off the cover and look for the relay that has a clear plastic cover on it. You can also power it on and home in on the click. There are several ways to clean it, but many don't recommend deoxit or contact cleaner. Some just use a piece of paper to rub between the contacts clean them.
 
Thanks for replies. I will try to locate the relay and clean pots. If that doesn't help, I guess, I will go with recapping. Hopefully, this will cure the receiver. As to use of oscilloscope, I am not at that level of knowledge yet :-( I will have to have it looked up by a technician.
 
The 2215B does not have a protection relay, rather it uses two 6v lamps for protection (they are painted red on the 700 pcb). The biggest culprit for noise and intermittent channel fading is the tape monitor switch, there is a tiny hole on the top of the switch, a little deoxit and cycle it about 30 times and you will be good to go. Then deoxit the selector and other pushbuttons for good measure. D5 is ok for switches, I never use it on pots, for those I use faderlube.

If you still have noise (particularly noise that sounds like frying eggs), you may have a leaky transistor on the preamp board. I just replace them all because they are cheap.
 
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