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Fisher 500B Right Channel Out

baymac

baymac

New Member
I just inherited my father's Fisher 500B. I remember it well from my youth. I'm a newbee here and not real technical. I have no drawings for this unit. I'm hoping for a home fix. But maybe this problem may be more serious. Here's my problem if anyone can help:

Right channel is not working at all. Balance control works fine. All other controls seem to work as well. Speakers are connected correctly according to other posts on this forum. Tubes have been cleaned and reseated and appear good. I noticed the phase reverse switch is sloppy and may be open. Haven't metered it out because i don't know if this switch affects the channel outputs? If so, can I bypass the switch to test? Any suggestions on what else to check to get right channel operating again.

I have it connected to a pair of KEF 204s and the left channel sounds great. Picks up distant FM stations perfectly. I'd like to restore this receiver but don't know for sure if I have inherited a dead soldier. Any comments appreciated.
 
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you should check the bias voltage on your output tubes to make sure you aren't killing them, it's described in many threads on this forum. you could switch output tube pairs to see if one is bad. the volume pot should be cleaned with some deoxit or contact cleaner as well as the speaker reverse switch. one of your pre amp tubes could be bad too, you could switch them side to side to check. restoration of this amp is detailed pretty well here, do a little searching, there's lots of good advice.
 
Could be a contact problem at one tube, switch, or control (does this one have the reverb in-out jacks? A short or poor contact there is a possibility).

There will be SOME output if one output tube is blown since there are two per channel - no need to look there for now.
 
Thank you very much for the tips. Now I have a good starting point. I'll post resusts. Thanks again..
 
channel problem

my fisher 400 had the same problem ..but after moving some tubes around it came back..i suggest you try that.
 
Check the space expander jack in the offending channel...if it is in to far-no sound. If it is not in far enough- no sound.
 
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