Sears Silvertone Hi Fi problem

I recently bought a silvertone Hi Fi at a yardsale. I do not know what year it is but I am guessing it is a late 60' early 70's model. It might even be an eighties model. Im not familiar enough with Hi Fis to really know. Everything seems to be working correctly, but for whatever reason when you play a record the pitch will not stay in tune. It has a pitch/speed control knob and it seems to work, but when you get it adjusted to the desired pitch/speed it will not stay there. Any suggestions on how to fix this problem? Here are some pictures of the knob that does the adjusting for the speed/pitch. The knob is located in the bottom right corner of the turntable. It would also be nice to know what the little window is supposed to be showing. I thought it had something to do with the speed/pitch adjustment, but know I am not sure. Any Ideas?

A phone call to Sears, giving them the model number, should get you a mfg. date. Ron Rich

I would try to clean the control (pot) with some Deoxit/tuner cleaner or similar products out there, and check out other semiconductors in that chain. --BB

Bobby Basham
Tucson, Arizona

Bobby Basham wrote:I would try to clean the control (pot) with some Deoxit/tuner cleaner or similar products out there, and check out other semiconductors in that chain. --BB

Bobby Basham
Tucson, Arizona

I didn't know they used potentiometer-controled electronic servo speed control in the 60-70's.

I've had some old tape decks back in the day that had pitch control. Some were external while others were inside with an adjustable pot. I don't know exactly what he's dealing with, just trying to help narrow things down abit. --BB

Bobby Basham
Tucson, Arizona

Stoopid question--exactly what is a "pitch control"--what does it do ?
TIA Ron Rich

Basically, a speed adjustment. Lower the motor speed, lower the pitch (key), something like on the old Pioneer, Technics, Marantz turntables back in the 80's. Ever notice how some record players play those records alittle bit too fast, while others seem to drag abit? That's just the nature of some of those beasts, and cannot be adjusted. I've got at least 8 consoles in the house and several large portables, using W610, W620, W621, W714 turntables, and they all seem abit different.

In cassette decks, I've found a "pot" inside the motor casing to adjust the speed, and some other decks had a separate mounted on the circuit board or out to an external pot that would do the same thing.

I don't know about the "Servo" thing or what the original posting has. Maybe he's talking about something completely different like a malfunctioning idler wheel that won't stay put. It would help if he took a close-up picture where this control is mounted. Is this the original turntable or did someone else drop in a replacement? --BB


Bobby Basham
Tucson, Arizona

Thanks, Bobby. I assumed that's what it was, but something in my feeble brain was questioning it ?
As a side note--in the old "Top 40 Radio" station daze, when a station was playing the "more music" game,
Some would run 45's as fast as 48 rpm--no one ever seemed to 'catch it"--- Ron Rich

The pitch knob is definitely external... to the bottom right of the turntable. I've added pictures. And yes it is the original turn table. It's easy for me to take more pictures if it helps. Thanks.

Ron Rich wrote:A pone call to Sears, giving them the model number, should get you a mfg. date. Ron Rich

I called sears yesterday, and they couldn't help at all. I was calling mostly looking for the owner's manual though, which I can't find anywhere.

You previously posted a picture with label indicating model 528.313141.01? If so the SAMS Photofact for the console excluding record changer is 1175-6. Unless I missed something you need to get the model number off the record changer. Then maybe you should get the SAMS for the changer.

Is this some kind of (not sure of the term), rheostat/adjustable resistor thingy, similar to a dimmer switch for a light fixture? --BB

Bobby Basham
Tucson, Arizona

It dont know if it is any kind of resistor or not. However it does work on a similar principle as a light dimmer. If you turn the knob all the way to the left it slows down the record. If you turn the knob to the right it speeds up the record. All I know is for whatever reason the record will not play at a stable speed. I do not work on record players as a hobby or anything. I know the basic concepts of a record player, but I do not know the mechanical aspects.

Have you looked the unit up on sears parts. I know on a DJ turntable when a pitch control goes bad you just replace it.

Also most turntable with a pitch control will have a center spot on the switch. this spot should set the table to the right speed then if you need to adjust it go from there. The deck table getting faster as it plays sounds like the switch needs a replacement. But not know the year of the deck some newer types use a pc board also with the switch.

If your pull the turntable from the console check to see if the switch is a potentiometer. Also a sing it needs to be clean is jerky when you turn it. I mean out a recored on the table you know what it should sound like. Turn the switch slow and fast and see if it sounds jerky as you turn it, Also this type of switch can be Rubbing alcohol and a toothpick. These switches get junk in them bad. pu night have to open the switch by prying the metal tabs to pull it a part.

this is a link to a atari site look at the bottom of the page to see this type switch in a paddle also shows how to clean one.
http://www.atariguide.com/help/care.htm

Yes I have looked the unit up o sears parts direct. It shows the list of parts, but most are unavailable. Plus, I dont know what the part I am looking for is called. They had a diagram showing the "breakdown" of the unit, but it did not really help any. I have also tried calling sears directly, but both attempts only got me directed back to their website. They couldnt even tell me the year it was made. All they could tell me was the availability of a particular part. Anyway, this particular model doesnt have a center spot on the control, but that in this situation is irrelevant. No matter the position of the control the speed is fluctuating. This is probably a stupid question, but how do I tell if the switch is a potentiometer?