Trouble with Sony TC-377

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-BNR-

New Member
Hi everyone, I'm an audio repair noob here, but I am very willing to learn. I am not new to electronics though! I have been assembling computers since I was 9! I do not know how to solder but I can easily learn if need be, I have plenty of motherboards with traces to practice on.

Anyways, my problem is with this particular reel to reel:
http://www.thevintageknob.org/SONY/sonyvault/TC377/TC377.html

The system powers on fine, but upon turning the knob to play (or rewind or fast-forward for that matter) the pinch roller comes out as it should but then makes a clicking sound and returns to its retracted position. I am guessing something is either wrong with some sort of spring that is connected to the knob or there is a problem with the motor. I can get pictures if needed (but not tonight) and maybe even a video. I have not opened the unit yet, as I wanted to get some advice before proceeding to do so. Thank you for any help! :)
 
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Yes, this is usually caused by the little tape sensor wire not moving freely. The Sony mechanism is designed not to engage if it can't sense that a tape is present. And when the linkages to these little sensor wires get sticky, the mechanism will simply refuse to engage.
 
Thank you all so much! I believe I have located the sensor. When I lift it up the play/ff/rw knob stays locked. How should I lubricate this little pin. Now that I can get the machine to engage I have run into another problem. The machine does not do anything when the knob is turned to play, rewind, or fast forward.
 
I've got a pdf of the TC-377 service manual if you'd like a copy. IIRC the manual is pretty good on dealing with mechanical issues. I bought one a few years ago for $10, replaced the belts and lubed/aligned all the mechanical bits. It's a good basic unit for what it is.
 
-BNR- said:
Thank you all so much! I believe I have located the sensor. When I lift it up the play/ff/rw knob stays locked. How should I lubricate this little pin. Now that I can get the machine to engage I have run into another problem. The machine does not do anything when the knob is turned to play, rewind, or fast forward.
Click to expand...

Maybe the most stupid question today - did you turn it on ?

(sorry - couldn't help myself :D )
 
I did actually turn it on! hahaha, but that is something I could see myself forgetting!

And Scuzzer, a copy of the pdf would be fantastic!
 
I've got two TC-377's. There is an internal drive belt that will break and cause your problem. I've had two break. The top cover is pretty easy to remove. just look for all the screws and remember that the knob for the tape LOCK lever has a left hand thread.
 
Scuzzer I found the manual online just now, that is less trouble for you, but thank you for the offer! :)


I now have the cover removed. One of the belts looks to have been stretched quite a bit. I powered on the system with the cover removed and attempted to rw,ff, and play (I used my finger to support the sensor) but what I believe to be the motors (I'm new at this :P) did not move.


Edit: Also, how should I make the sensor more "limber".
 
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think the tapesensor is attached to a microswitch that turns on the motor - can you hear a click when moving the tapesensor ?
 
-BNR- said:
It is off, and I can not see the motor running, which is what I am assuming to be the problem.
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To see the motor run on these units you must take the back cover off. With that removed you will see the entire motor. There is a little fan attached to the back of the motor which you will hear if the motor is engaged. I had a 377 and gave it to my girlfriends brother. Great sounding deck and those ferrite heads are the best. I would look for any loose wires in the back of the unit. Follow the wire from the microswitch to the back of the unit.
 
377pulley.jpg
ShaneR2R said:
To see the motor run on these units you must take the back cover off. With that removed you will see the entire motor. There is a little fan attached to the back of the motor which you will hear if the motor is engaged. I had a 377 and gave it to my girlfriends brother. Great sounding deck and those ferrite heads are the best. I would look for any loose wires in the back of the unit. Follow the wire from the microswitch to the back of the unit.
Click to expand...

when the frontplate is off you can se the idler turn - there is a belt from the motors pulley to the left idler.

if the motor isnt running it could be - switch, motorcapacitor or the motor itself ....
 
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jan_stevns said:
377pulley.jpg


when the frontplate is off you can se the idler turn - there is a belt from the motors pulley to the left idler.

if the motor isnt running it could be - switch, motorcapacitor or the motor itself ....
Click to expand...

Yes that is true you can see the idler wheel turn if the motor is working.
 
You need to have the power switch on and the tape sensor pushed towards the erase the head in order for the motor to run.

edit: oops, I just saw that someone else mentioned that.
 
I'll let you handle it Jan, I'm a relative noob when it comes to RTR. I was just curious what was the least amount of things I had to do to get the motor to spin. Power on and sensor pushed up was all it took.
 
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