Panasonic K-mech VCR problems

[Stein-Olav Lund]

I have some trouble with a Blaupunkt RTV-936EN VCR, which has a K-mech.
It sometimes plays well, but then suddenly it starts to make tape
noises, the backtension arm flutters, and switches off. If I switch on
again the tape is difficult to eject. I have cleaned away some lint and
also removed the 'head cleaner' felt roll, as I understand this makes
more trouble than it solves.
Is there an easy fix to this problem? I have tried to find a description
of the K-mech on the net without luck. Do you know of VCR mech
descriptions on the net?
Any info is welcome.

Stein

 

[Mark D. Zacharias]

If this model has the soft-brake type back-tension arm, used in later model
years, I've seen lots of problems with these which sound exactly like your
problem. The felt on the back tension arm get occluded with crud, and there
is way too much back-tension. The machine grinds to a halt.

This may not apply to yours - if yours uses a more typical type back-tension
band, it's less likely, but your problem could still be in this area.


Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stein-Olav Lund" <stein.o.lund@iet.hist.no> wrote in message
news:c6q79o$c7b$1@dolly.uninett.no...

I have some trouble with a Blaupunkt RTV-936EN VCR, which has a K-mech.
It sometimes plays well, but then suddenly it starts to make tape
noises, the backtension arm flutters, and switches off. If I switch on
again the tape is difficult to eject. I have cleaned away some lint and
also removed the 'head cleaner' felt roll, as I understand this makes
more trouble than it solves.
Is there an easy fix to this problem? I have tried to find a description
of the K-mech on the net without luck. Do you know of VCR mech
descriptions on the net?
Any info is welcome.

Stein

 

[Stein-Olav Lund]

Mark D. Zacharias wrote:

If this model has the soft-brake type back-tension arm, used in later model
years, I've seen lots of problems with these which sound exactly like your
problem. The felt on the back tension arm get occluded with crud, and there
is way too much back-tension. The machine grinds to a halt.

This may not apply to yours - if yours uses a more typical type back-tension
band, it's less likely, but your problem could still be in this area.

Mark, I don't know the VCRs that well that I can establish that it has a
soft-brake b.t.arm ..
The bearing on the backtension arm seemed a bit stiff, I cleaned and
lubed it as best I could and the machine seems to work well afterwards.
I played a long tape yesterday without any problems, cycling all operations.
Ola Thoren reported about cracked screw on the loading motor, but I
can't find it is loose or cracked. I have watched the loading motor
spindle when operating, it moves a little longitudinally, but I believe
this only is slack in the motor.
Is this really the problem after all?

Stein

Mark Z.

 

[Mark D. Zacharias]

The ones I've seen with the cracked loading motor wormscrew seemed to work
OK until REWIND mode was entered, then would make a sick mechanical noise
and lock up the mech. Only seen this a couple times, though.

The back-tension arm is about the first or second thing the tape touches as
it exits the tape cartridge on the left side, as viewed from the front - top
side. It should be in contact with the inside of the tape itself, applying
pressure to the left against the tape, and sort of "floating" as it
continually applies / releases pressure. Sort of a mechanical servo. If you
were able to load the tape carriage without a tape, you could see the
back-tension device, whichever type, applying a felt surface to the supply
hub. You can see it's action by taking your finger and pushing the tension
arm in slightly, to the right, and the felt band will loosen visibly.
In some cases the felt has become detached partially or completely, and on a
close inspection this would be obvious.


Mark Z.

--
Please reply only to Group. I regret this is necessary. Viruses and spam
have rendered my regular e-mail address useless.


"Stein-Olav Lund" <stein.o.lund@iet.hist.no> wrote in message
news:c6tf6m$bd2$1@dolly.uninett.no...

Mark D. Zacharias wrote:
If this model has the soft-brake type back-tension arm, used in later
model
years, I've seen lots of problems with these which sound exactly like
your
problem. The felt on the back tension arm get occluded with crud, and
there
is way too much back-tension. The machine grinds to a halt.

This may not apply to yours - if yours uses a more typical type
back-tension
band, it's less likely, but your problem could still be in this area.

Mark, I don't know the VCRs that well that I can establish that it has a
soft-brake b.t.arm ..
The bearing on the backtension arm seemed a bit stiff, I cleaned and
lubed it as best I could and the machine seems to work well afterwards.
I played a long tape yesterday without any problems, cycling all
operations.
Ola Thoren reported about cracked screw on the loading motor, but I
can't find it is loose or cracked. I have watched the loading motor
spindle when operating, it moves a little longitudinally, but I believe
this only is slack in the motor.
Is this really the problem after all?

Stein


Mark Z.