wrote:
Mr. Mike wrote:
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

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