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-   -   sherwood s-8900 (http://www.diyaudio.com/forums/solid-state/149237-sherwood-s-8900-a.html)

steven344 22nd August 2009 09:17 AM

sherwood s-8900
 
Im working on a sherwood s-8900 and cant figure out why both channels are not working.I have audio getting to the output stage ,nothing is shorted.Its an old school amp but Im trying to fix it for someone

steven344 22nd August 2009 09:19 AM

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east electronics 22nd August 2009 09:44 AM

there can be a number of reason (s) but the most serious are two

one all switches and pots will need very good cleaning with a good quality spray for cleaning ( please read related threads about all that since not every spray is switable for that and also how much spray is an issue )
two beyond that you will need to make shure that all small electrolytics still work properly ....there is a very good chance that they are seriously gone to mars ....

after that you may wana ta ke a look at that and find it very handy

http://www.diyaudio.com/forums/showt...261&highlight=

sregor 22nd August 2009 04:03 PM

IF everything is okay to the outputs - possibilities are speaker selector switch, fuses or fuse holders if they use them. (don't have schematic handy) Another possibility us that some of the old sherwood amps use series connection for speakers - nothing works in a + b speaker mode unless speakers are hooked to both.

djk 22nd August 2009 06:05 PM

Look for DC at the amplifier's output (at the speaker relay).

If it's OK, the speaker relay is not pulling in.

The timing cap in the relay circuit is probably dried up.


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