Stink Bear
Active Member
I recently got this 2215B. One channel was weak and distorted, I'm almost positive it was the right channel. I swapped the output transistors side to side, the problem moved to the other channel. I didn't see any evidence of burned components, and the bad channel sounded good (I thought) with the output transistors swapped. I believe I did some checking of other components in circuit with an ohmmeter but I don't remember for sure, I've been working on a few units recently.
Also, this unit looked like it had gotten wet at some point, dirty water stains on the cabinet. There is a little corrosion on the inside but not too bad. I did some cleaning with alcohol and a paint brush but I should probably get some electronic parts cleaner and spray it down well.
At any rate I installed replacement transistors, no more weakness / distortion, but I noticed some time later that the left channel has static (a low volume crackling) on FM that is associated with sound. If there is no sound (music, talking DJ) I don't hear static.
It's worse when I first power up the unit, gets better after just a few minutes.
It sounds worse when I turn the bass all the way down and the treble all the way up.
No static on tape monitor when playing a cassette tape.
I don't think I get static on AM but it's hard to tell as I don't receive any AM stations well.
I think this indicates a problem with the FM tuner, but what kind of problem I don't know. I don't have any electronic parts cleaner right now. I was thinking of cleaning the tuner ground contacts, but I suspect only hearing the static in the left channel it is more likely a bad component.
I did search the forum but I didn't find any threads that addressed the same symptoms I have. Anyone have any advice?
Thanks
Also, this unit looked like it had gotten wet at some point, dirty water stains on the cabinet. There is a little corrosion on the inside but not too bad. I did some cleaning with alcohol and a paint brush but I should probably get some electronic parts cleaner and spray it down well.
At any rate I installed replacement transistors, no more weakness / distortion, but I noticed some time later that the left channel has static (a low volume crackling) on FM that is associated with sound. If there is no sound (music, talking DJ) I don't hear static.
It's worse when I first power up the unit, gets better after just a few minutes.
It sounds worse when I turn the bass all the way down and the treble all the way up.
No static on tape monitor when playing a cassette tape.
I don't think I get static on AM but it's hard to tell as I don't receive any AM stations well.
I think this indicates a problem with the FM tuner, but what kind of problem I don't know. I don't have any electronic parts cleaner right now. I was thinking of cleaning the tuner ground contacts, but I suspect only hearing the static in the left channel it is more likely a bad component.
I did search the forum but I didn't find any threads that addressed the same symptoms I have. Anyone have any advice?
Thanks