Classic Hifi Care

I visited the local st.vincent depaul store and found a sony R2R tc-355 sitting on the floor , when I inquired about it I was told it did not work and only good for parts , so I got it for 10 bucks ... when I got it home I plugged it in and overrode the tape sensor.. the reel tables turned fine...until I looked closer ... the main motor runs in reverse, since it is a induction motor I figured it was wired wrong, but there are only 3 wires, and they only connect one way ... don't know how this could happen unless the motor has a burnt winding internally ...so unless I can find a motor for it I will strip it... anyone need any parts?

Could there be a rewind switch or linkage somewhere that is causing the issue? Seems like the motor wouldn't reverse itself. IF there was a short in the motor, wouldn't there be some other indication of that? Good luck.

Hey Elton, I think my Sony R to R is that model number. I'll check and get back to you.

Bill

hermitcrab wrote: ↑Sat Dec 03, 2022 7:07 pm I visited the local st.vincent depaul store and found a sony R2R tc-355 sitting on the floor , when I inquired about it I was told it did not work and only good for parts , so I got it for 10 bucks ... when I got it home I plugged it in and overrode the tape sensor.. the reel tables turned fine...until I looked closer ... the main motor runs in reverse, since it is a induction motor I figured it was wired wrong, but there are only 3 wires, and they only connect one way ... don't know how this could happen unless the motor has a burnt winding internally ...so unless I can find a motor for it I will strip it... anyone need any parts?

Starting cap issue? Seems a shame to junk it for such a simple problem.

Chris Campbell

But if you are going to strip it, I wonder if the heads are the same as on the TC 350. Mine needs a second replacement set.

Chris Campbell

Elton, I checked my model and it's a Sony TC558. I'm guessing the parts are not the same.

Bill

I have been experimenting ... this particular motor the mounting brackets can be mounted either end , so I took it out flipped the motor over and re installed so it now play s the correct direction , but the motor is toast... has no torque unless the voltage selector is on 100v , putting it to 117 or 120 and it stalls out while trying to play a tape , But I think I may have found one .. we have a guy locally in our area that advertises on FB that has all kinds of electronic parts and he claims he might have one ... I kinda figured the motor was bad as the resistance readings are all goofy on the windings ...bill is your machine a auto reverse set?

Mine is auto reverse, but I'm not sure how that works. Is there something that on the tape that triggers it to reverse? Mine is a three-motor unit and it's only problem is weak treble/highs on the left channel in forward. In reverse, it's ok. I actually had it gone thru, I was not going to touch the electronics on this one. A bunch of caps were replaced along with resistors and all controls cleaned. It definitely sounds better but still the left channel is weak with treble/highs. The only thing left is a weak or defective head. At least that is my guess.

Bill

William wrote: ↑Mon Dec 05, 2022 1:04 am Mine is auto reverse, but I'm not sure how that works. Is there something that on the tape that triggers it to reverse?

Some devices used a bit of conductive foil spliced in at the ends. Later the better ones used a recorded signal, some sort of low frequency flutter, I think. to trigger the direction change.

And for the high-frequency loss on one channel, one direction, have you examined the heads carefully to make sure there's no petrified goo stuck to the playback head on one track-width?

Chris Campbell

Chris, was the foil and signal built into blank tapes or was that only on store bought recorded tapes?

The heads have been checked, cleaned with everything one could think of including Acetone. Having the Sony professionally serviced did make a difference in treble/high performance, but it did not cure the problem.

Bill

You could splice in the foil, as I recall. Think I have a roll of it somewhere.

As to HF loss, worn heads can do that as the gap opens.

Chris Campbell

Thanks, Chris. I never knew how the auto reverse thing worked.

Bill

Fixed the motor!... I found that the motor could spin easily the wrong way.. but jammed going the correct way, so I took apart , I figured what do I have to lose?... these sony motors come apart easily. as soon as I split the case parts stated falling out... the plastic spacer used to prevent the spinning stator from bottoming out on the bearing had disintegrated, allowing the motor ro jam ... I went to local hardware and found nylon washers with the correct diameter hole to take up place of the missing spacer, threw it back together and it started right up turning the right way with plenty of torque... I almost stripped the whole machine for a 50 cent part... another reason when I buy for parts I have to see if it truly is a parts only candidate or can be saved ... also Ampex machines used a system to detect the signal that could reverse the tape... don't know of any other brands that did that other than using the foil...

Glad that you solved the problem. It always seems a shame to junk a device that isn't made any more.

Chris Campbell

Great job! It is always good to hear when someone saves a worthy device from destruction.

I still have a box of doodads you can put on tape to trigger the auto-reverse mechanism. Some of the premium tape had it from the factory. What I have looks like foil with a clear tape over it that is sticky. I had an auto-reverse cassette deck that I sold at the auction.