Sony TC-758 reel to reel won't play

[Mr. Mike]

I have a Sony TC-758 reel to reel tape recorder which was given to me by a
friend. It hasn't been used for many years, but allegedly worked prior to it
being given to the friend. But now it doesn't work properly.

There are 5 buttons on the right of the machine which control stop, play, fast
forward, reverse play and rewind (this machine has auto-reverse). It works fine
for fast forward and rewind ... the tape gets up to a good speed.

But when you push "play" or "reverse play," the rubber wheels in front of the
playback heads don't move the tape forward so it will play. There is a
"clicking" noise, and some slight motion in the rubber wheels and the mechanism
underneath, but that's it. Rather than playing, the tape starts to fast forward
or rewind, though not as fast as the actual fast forward or rewind speeds.

Here is a more detailed explanation:

If you take off the cover over the heads, there are two "poles" that the cover
slips down over on the right and left. To the left of the left "pole," when you
push "play" (in either direction), there is some metal thing underneath down
inside below the surface (like a lever) which moves slightly to the left (the
one on the right side does not move at all) -- this is connected to the
mechanism that causes the rubber heads to push the tape up against the playback
heads so the tape will be heard -- accompanied by a clicking noise. I took a
stick and pushed this left lever slightly to the left ... and it makes a
clicking noise (tick-tick-tick-tick-etc.) like a telegraph machine.

I made a brief video (about 9 megs in size) which illustrates this.

http://www.mjq.net/misc/video.avi

Any idea what is wrong? Is this an electrical problem, or does it just need some
lubrication and/or a good push (not off a dock ?

 

[[email protected]]

But when you push "play" or "reverse play," the rubber wheels in front of the

playback heads don't move the tape forward so it will play. There is a
"clicking" noise, and some slight motion in the rubber wheels and the mechanism
underneath, but that's it. Rather than playing, the tape starts to fast forward
or rewind, though not as fast as the actual fast forward or rewind speeds.

What you are probably looking at is either a worn out/deteriorated
drive belt(most likely fixable) or a broken gear(probably not fixable).
In any event the source of your trouble should be easily observed if
you remove the rear of the unit.

push "play" (in either direction), there is some metal thing underneath down
inside below the surface (like a lever) which moves slightly to the left (the
one on the right side does not move at all) -- this is connected to the
mechanism that causes the rubber heads to push the tape up against the playback
heads so the tape will be heard -- accompanied by a clicking noise. I took a

Clicking noises would seem to implicate either partial engagement on a
set of gears or a gear that has broken teeth. If that's the case all I
can say is I wish you good luck finding parts.

Hope this helps.

Chris

 

[[email protected]]

What you are probably looking at is either a worn out/deteriorated
drive belt(most likely fixable) or a broken gear(probably not fixable).
In any event the source of your trouble should be easily observed if
you remove the rear of the unit.

yes, you the OP are the one in a position to uncover the mechanism,
observe its action, see where its going wrong and fix it. These sort of
problems are not well suited to asking remote advice about.


NT

 

[Mark D. Zacharias]

I have a Sony TC-758 reel to reel tape recorder which was given to me
by a friend. It hasn't been used for many years, but allegedly worked
prior to it being given to the friend. But now it doesn't work
properly.

There are 5 buttons on the right of the machine which control stop,
play, fast forward, reverse play and rewind (this machine has
auto-reverse). It works fine for fast forward and rewind ... the tape
gets up to a good speed.

But when you push "play" or "reverse play," the rubber wheels in
front of the playback heads don't move the tape forward so it will
play. There is a "clicking" noise, and some slight motion in the
rubber wheels and the mechanism underneath, but that's it. Rather
than playing, the tape starts to fast forward or rewind, though not
as fast as the actual fast forward or rewind speeds.

Here is a more detailed explanation:

If you take off the cover over the heads, there are two "poles" that
the cover slips down over on the right and left. To the left of the
left "pole," when you push "play" (in either direction), there is
some metal thing underneath down inside below the surface (like a
lever) which moves slightly to the left (the one on the right side
does not move at all) -- this is connected to the mechanism that
causes the rubber heads to push the tape up against the playback
heads so the tape will be heard -- accompanied by a clicking noise. I
took a stick and pushed this left lever slightly to the left ... and
it makes a clicking noise (tick-tick-tick-tick-etc.) like a telegraph
machine.

I made a brief video (about 9 megs in size) which illustrates this.

http://www.mjq.net/misc/video.avi

Any idea what is wrong? Is this an electrical problem, or does it
just need some lubrication and/or a good push (not off a dock ?

Looks like mainly lubrication issues, but this mechanism also uses belts to
accomplished the auto-reverse by flipping the head block around. This belt
(or 2 - don't exactly remember) will also need changing, and the head block
removed and disassembled for re-lubrication. This type of repair is best
left to professionals.


Mark Z.

 

[[email protected]]

The belts are probably like old rubber bands, cracked, hard, not
flexible, etc. I have actually used similarly sized new rubber bands
as a temporary belts just to see if things would work. Getting the
correct belts will be a problem, so using the rubber band approach will
at least give an idea if getting the belts will solve the problems.

H. R. (Bob) Hofmann

 

[[email protected]]

I have a Sony TC-758 reel to reel tape recorder which was given to me by a
friend. It hasn't been used for many years, but allegedly worked prior to it
being given to the friend. But now it doesn't work properly.

There are 5 buttons on the right of the machine which control stop, play, fast
forward, reverse play and rewind (this machine has auto-reverse). It works fine
for fast forward and rewind ... the tape gets up to a good speed.

But when you push "play" or "reverse play," the rubber wheels in front of the
playback heads don't move the tape forward so it will play. There is a
"clicking" noise, and some slight motion in the rubber wheels and the mechanism
underneath, but that's it. Rather than playing, the tape starts to fast forward
or rewind, though not as fast as the actual fast forward or rewind speeds.

Here is a more detailed explanation:

If you take off the cover over the heads, there are two "poles" that the cover
slips down over on the right and left. To the left of the left "pole," when you
push "play" (in either direction), there is some metal thing underneath down
inside below the surface (like a lever) which moves slightly to the left (the
one on the right side does not move at all) -- this is connected to the
mechanism that causes the rubber heads to push the tape up against the playback
heads so the tape will be heard -- accompanied by a clicking noise. I took a
stick and pushed this left lever slightly to the left ... and it makes a
clicking noise (tick-tick-tick-tick-etc.) like a telegraph machine.

I made a brief video (about 9 megs in size) which illustrates this.

http://www.mjq.net/misc/video.avi

Any idea what is wrong? Is this an electrical problem, or does it just need some
lubrication and/or a good push (not off a dock ?

Now THAT goes back to '73-'76 - the auto-reverse version of my TC-755.
Mark Z. says to leave it to someone who is comfortable stripping it
down and he's absolutely correct. Sell it on eBay?

Somewhere in the garage I have a service manual on the 755 which is
close enough to get it going but unless you have some old 1/4" tapes to
transfer, why bother? Parts are difficult to impossible to get. The
heads were "F&F" (ferrite and ferrite) which sounds good on paper but
in fact had terrible life. Look at them under a microscope and you
likely see the gap full of pock-marks. When they were new, they worked
well but it only took a few hundred hours to deteriorate. BTW the Akai
GX (glass and crystal ferrite) were crap, too. Your computer sound card
and some software is a better recorder than the analog decks ever were.

FWIW, you have it threaded wrong in your video. Tape goes under the
movable, OVER the first fixed guide, through the head area, over the
last fixed and under the movable.

The pinch roller solenoid(s) (I think there are 2, 1 for pause) have
microswitches to lower the power input after they pull in. Those
micros, (also used under the transport control buttons) are known PITA
devices. Not reliable at all. Assuming the linkages aren't gummed up,
may be why you're getting the 'clicking'.

GG

 

[b]

I have a Sony TC-758 reel to reel tape recorder which was given to me by a
friend. It hasn't been used for many years, but allegedly worked prior to it
being given to the friend. But now it doesn't work properly.

There are 5 buttons on the right of the machine which control stop, play, fast
forward, reverse play and rewind (this machine has auto-reverse). It works fine
for fast forward and rewind ... the tape gets up to a good speed.

But when you push "play" or "reverse play," the rubber wheels in front of the
playback heads don't move the tape forward so it will play. There is a
"clicking" noise, and some slight motion in the rubber wheels and the mechanism
underneath, but that's it. Rather than playing, the tape starts to fast forward
or rewind, though not as fast as the actual fast forward or rewind speeds.

Here is a more detailed explanation:

If you take off the cover over the heads, there are two "poles" that the cover
slips down over on the right and left. To the left of the left "pole," when you
push "play" (in either direction), there is some metal thing underneath down
inside below the surface (like a lever) which moves slightly to the left (the
one on the right side does not move at all) -- this is connected to the
mechanism that causes the rubber heads to push the tape up against the playback
heads so the tape will be heard -- accompanied by a clicking noise. I took a
stick and pushed this left lever slightly to the left ... and it makes a
clicking noise (tick-tick-tick-tick-etc.) like a telegraph machine.

I made a brief video (about 9 megs in size) which illustrates this.

http://www.mjq.net/misc/video.avi

Any idea what is wrong? Is this an electrical problem, or does it just need some
lubrication and/or a good push (not off a dock ?

you need to first see if the heads and electronics are in good
condition before spending good money on it, but it looks like a nice
deck and probably worth persevering with.

chances are, the lubricant or grease on the pinch roller mechanism has
hardened and just needs replacing, but that is the simple part. First
you will have to dismantle it which would probably be beyond you if you
have no experience. it may be easier to post your area on yahoo groups
reel to reel (need to join first) or www.tonbandwelt.de (there is a
forum with an english section). to see if there is anyone within a
rerasonable distance of your home to whom you could take the deck I am
sure you will get some results that way.
regards,
-B.

 

[aafuss]

Now THAT goes back to '73-'76 - the auto-reverse version of my TC-755.
Mark Z. says to leave it to someone who is comfortable stripping it
down and he's absolutely correct. Sell it on eBay?

Somewhere in the garage I have a service manual on the 755 which is
close enough to get it going but unless you have some old 1/4" tapes to
transfer, why bother? Parts are difficult to impossible to get. The
heads were "F&F" (ferrite and ferrite) which sounds good on paper but
in fact had terrible life. Look at them under a microscope and you
likely see the gap full of pock-marks. When they were new, they worked
well but it only took a few hundred hours to deteriorate. BTW the Akai
GX (glass and crystal ferrite) were crap, too. Your computer sound card
and some software is a better recorder than the analog decks ever were.

FWIW, you have it threaded wrong in your video. Tape goes under the
movable, OVER the first fixed guide, through the head area, over the
last fixed and under the movable.

The pinch roller solenoid(s) (I think there are 2, 1 for pause) have
microswitches to lower the power input after they pull in. Those
micros, (also used under the transport control buttons) are known PITA
devices. Not reliable at all. Assuming the linkages aren't gummed up,
may be why you're getting the 'clicking'.

GG

Hi,
I would like the 755 manual scanned in and sent as pdf-as I collect
Sony SM's?

 

[Ohmster]

But when you push "play" or "reverse play," the rubber wheels in front
of the playback heads don't move the tape forward so it will play.
There is a "clicking" noise, and some slight motion in the rubber
wheels and the mechanism underneath, but that's it. Rather than
playing, the tape starts to fast forward or rewind, though not as fast
as the actual fast forward or rewind speeds.

Ugh, I have done so many of these in my day it is not funny. I just got
tired of doing them and now do TV sets, more fun. Wheeeeeeeeeeeee!

Okay, I saw your video. You want to really know what is wrong and how to
fix it, for real? Okay, listen up.

The "rubber wheels" are called pinch rollers and they must engage the
"rotating pole" which is called the capstan. This pinching of the tape
between the pinch roller and the constant motion of the capstan is what
gives the tape a forward (Or reverse) motion that is constant and steady,
just what you need for playback.

What happens when you push play is that part of the mechanics is to move
those pinch rollers against the capstans. This is done either by a
solenoid or just a mechanical lever moving another lever which pushes the
pinch roller against the capstan. This lever is actually an L shaped
lever or could be straightish, but the fulcrum of this lever is actually
a sleeve bearing and when it was in good condition, was lubricated with a
good quality machine oil. Now the oil is all dried up and has turned into
goo. You must remove all the crap on top of the machine and take the top
plate off to expose this lever.

Carefully remove stuff, a little at a time, and lay it out so that you
can remember how to put it back. A digital camera will help here, take
pictures as you go along to make yourself a diagram of how to reassemble
the unit when you are done. Remove this lever and clean it out with Q-
Tips and alcohol, acetone, nail polish remover, or whatever good solvent
you have laying around. Lubricate the shaft and the inside of the sleeve
bearing with good quality machine oil, 3 in One works good, and
reassemble everything. Adjust as necessary and you are done. The machine
will work again. Now you probably will need all new belts and maybe the
rubber idler tires (Rubber traction wheels) inside might also be dried
out. If they are not too bad, they make a rubber reconditioner to make
the wheels soft again. The belts will have to be replaced.

Is it worth all this trouble? Probably not, but you did ask and you got
your answer. Cheers.