Pioneer SX-850 Help!

**FireWalker877** · **06-29-07, 09:58 PM**

My father purchased a Pioneer SX-850 while he was in the navy. I recently connected it to the monitor outputs on a Samsung television and had a LOT of distortion. I noticed that whenever I turned the volume knob, the left channel would crackle and cut in and out. This happens on only one of the input channels. (I asked my father if he knew what the problem was, and he thought it was the left speaker...

) I have never attempted to service a vintage receiver, and wondered if anyone had any suggestions as to what the problem might be. Since it will be connected to a tape deck, turntable, and television, I need all three inputs to work. Should I just try to find an repair shop?

(Those AR-52's that I still need to put new surrounds on will eventually be connected to this 40 lb monster.)

**Sonnie** · **06-30-07, 12:20 AM**

You might try opening it up and cleaning it... maybe use some contact cleaner on the volume control. Who knows, it might just need a little TLC. Short of that, I'd suggest a repair shop. lcaillo, our Therapist, could probably give you some advice on this if you wanna PM him.

**Otto** · **06-30-07, 09:10 AM**

Yep, Sonnie has the right idea, IMHO. Unplug it completely, open it up, find the volume potentiometer from the inside and carefully spray it with some contact cleaner (available at Radio Shack for about $10). Work the pot back and forth as if you're lubricating it, wait a few minutes for it to dry and reconnect everything. I bet your crackling with the volume is gone.

**lcaillo** · **06-30-07, 09:19 AM**

Get some good contact cleaner. The best that I know of is Caig's DeOxit, formerly known as Cramolin. With a unit this old you want to be very careful not to damage the controls as they are likely not available.

**F1 fan** · **06-30-07, 12:37 PM**

Like lcallio suggested use a good contact cleaner and avoid one that contains silicone like the stuff RS sells.

**FireWalker877** · **06-30-07, 01:26 PM**

Alright, guys, I'm gonna open her up! I will post some pics of what I find. It might be fun to compare innards from 30 years ago with today's.

Hopefully it is just the volume knob, but I have a feeling there is something more sinister at work here.

**Otto** · **06-30-07, 01:35 PM**

Hi guys,

Just wondering, what makes a good/bad contact cleaner? I've used the RS stuff with good results, but mostly on old guitar parts and such. Never had a scratch come back in a pot. How does the silicone make it bad? Or any other ingredient for that matter. I'm no expert on contact cleaner...

**lcaillo** · **06-30-07, 08:30 PM**

A good contact cleaner, IMO, has enough solvent to break up the goo and corrosion, a lubricant that does not cause more problems than it solves, and does not attach the plastics or other parts. The Caig products are the best I have used, but I also use a more standard cleaner with a silicon lubricant when I need to use a lot to get into a hard to reach pot. I then use the DeOxit to finish it, as it is much more expensive.

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