Pioneer SX 780: Right Channel Distortion

[erosario]

Hey All, would definitely appreciate any help or insight on a slight issue.

Bought a Pioneer SX 780 (beautiful for its condition :thmbsp. The issue I am having is distortion coming from the right channel.

I have tried switching out speakers and the distortion still comes from the right.

Might some deoxit do the job or might it be something else. According to its history, it was serviced not too long ago. There are no scratchy pots. Everything is smooth and this issue has recently come up. Thought it was my vinyl but its not.

The issue occurs when on Phono, Aux, Tape, and on the Radio Setting. Works fine when I plug in headphones .

Any insight would help. Thanks guys.

 

[qprhooligan]

Is it distorted with all inputs? Clean controls first with dioxin. If that doesn't fix it check the relay by tapping it to see if it gets better or worse.

 

[larryderouin]

Distortion in speakers and none in headphones on a 780, to me points right at the emitter resistors, or a marginal pack. R262,263,264,265. .22ohms 2W. There's 4 of them, 2 per channel.

hooligan, you really want those contacts untouchable!! I can think of better uses for Dioxin.....

 

[erosario]

thanks, appreciate the help guys :thmbsp:

 

[markthefixer]

can do now:

swap packs (test resistors while swapping packs, if resistor bad, bad pack blew resistor or resistor blew pack),
note - sometimes NO resistors, they're 0.22 ohms and factory installed wires instead...
see if distortion moves. If moves, pack's fault...

if not:

protection relay contacts? worth checking...
temporarily bridge contacts when distorting (screwdriver blade?), if still distorting, further troubleshooting needed.