Sony SLV-686HF won't rewind

[Shawn Lin]

I have a Sony SLV-686HF that won't rewind.
High speed rewind results in the tape being loaded/unloaded repeatedly
until the VCR gives up and quits.
Normal rewind results in the tape rewinding for anywhere between 3 and
30-seconds before the VCR just quits.
Reverse scan during playback doesn't work either.
Fast forward works.
Playback works fine.

The load arm is fully lubricated and moves freely.
The capstan motor flywheel was previously rubbing on the windings,
causing stop & go playback operation as well as severe binding. With
pliers and vise-grips, I carefully bent the vertical part of the
housing to where the flywheel no longer rubs the windings and spins
freely. That completely fixed all playback issues. I just wonder if
the damaged windings has resulted in a weak motor that cannot supply
the torque required for rewinding?

Has anyone encountered this before and know the cause?

Thanks,

Shawn

 

[Jeff Wiseman]

The capstan motor flywheel was previously rubbing on the windings,
causing stop & go playback operation as well as severe binding. With
pliers and vise-grips, I carefully bent the vertical part of the
housing to where the flywheel no longer rubs the windings and spins
freely. That completely fixed all playback issues. I just wonder if
the damaged windings has resulted in a weak motor that cannot supply
the torque required for rewinding?

I'm not familiar with that unit but I wonder if the question that you should REALLY ask is how did the unit get to the point that the flywheel was rubbing? Unit dropped? Tape violently yanked out? Bearings worn out? Obviously, the capstan mechanism is not in the shape it was intended to be and low torque is a possible side effect.

Just my $.02 worth

- Jeff

 

[Sofie]

Shawn Lin:
Pliers and Vise-Grips? ...... bending ?
Common failure item is the capstan bearing assembly.... and as a possible
result of the rubbing and severe binding, the motor and drive circuitry
overheated and/or the motor windings have been damaged.
Instead of "pliers and vise grips... and bending" a REPLACEMENT of the
bearing was the first move and if done right away usually fixes all the
problems. At this point however you may have to replace the capstan motor
too. Fulton Radio (search the web) will have the OEM parts you need to do a
proper repair.

 

[Shawn Lin]

I didn't realize the bearing was replaceable, but I didn't notice any
lateral play in the capstan so I didn't think it was a bearing.
Bending the vertical part of the housing resulted in super smooth
mechanical movement and no touching of the windings, so I thought it
should be okay as far as "fudge fixes" goes. I had actually performed
this same "fudge fix" 3 or 4 years ago to my SLV-585HF with no ill
effects (rewind and fast rewind works fine on it). That VCR has been
on severe duty since the fix and has been super reliable, so don't
discount the power of bending so quickly! I suppose I just caught the
problem faster on the 585HF. There's just no reason for me to sink
any money into a VCR whose value is only $20. Check Ebay's completed
auctions and you'll see the highest a 686HF has gone for is $21.51. I
suppose we can thank the DVD revolution for the low dollar amounts
these old workhorses fetch.
Anyway, I was just wanting to fix it to sell on Ebay, however, they go
so low that if I have to put any money into it at all, it's probably
not worth bothering. Even if a bearing would fix it, that comes close
to exceeding the value of the VCR.

FWIW, the VCR seems to be giving me an error message. On normal
rewind when it stops, I get:

Lh 16m 02s

On high speed rewind, I get:

Lh 07m 02s

Incidentally, the exact same problem as this guy has:

http://groups.google.com/groups?hl=...ueg%24sia8%241%40knows.shr.cpqcorp.net&rnum=2

The guy never posted back with what fixed it, so I might swap the
capstan motor out of the 585HF, put it in the 686HF and see what
happens.

Shawn

 

[Shawn Lin]

I'm not familiar with that unit but I wonder if the question that you should REALLY ask is how did the unit get to the point that the flywheel was rubbing? Unit dropped? Tape violently yanked out? Bearings worn out? Obviously, the capstan mechanism is not in the shape it was intended to be and low torque is a possible side effect.

A quick web search on this model and its siblings (585HF, 595HF,
696HF, etc.) indicates that this is a rather common problem with this
model.
In fact, a previous 585HF I still own had this problem when I bought
it. It might be just a bearing, but I didn't want to sink any money
into it and the bending of the capstan housing worked perfectly on it
and has held up for 3-4 years now!
I think the flywheel may have damaged the windings resulting in low
torque on this one because the problem wasn't caught soon enough.

Shawn

 

[Sofie]

Bending the vertical part of the housing resulted in super smooth
mechanical movement and no touching of the windings, so I thought it
should be okay as far as "fudge fixes" goes. I had actually performed
this same "fudge fix" 3 or 4 years ago to my SLV-585HF with no ill
effects (rewind and fast rewind works fine on it). That VCR has been
on severe duty since the fix and has been super reliable, so don't
discount the power of bending so quickly!

----------------------

Shawn Lin:
Actually, what I was mostly concerned about when you described your"bending"
"fudge fix" with the pliers and vise grips....... was the proper and
critical perpendicular alignment of the capstan shaft to the deck plate as
it relates to the pinch roller and the video tape. Any significant
deviation can cause tracking and interchange problems, tape creasing, and
lots of other nasty problems...... relieving the scraping of the motor coils
was certainly a primary task that you properly identified but this is a
precision part so I cringed a little (actually I cringed a lot) when you
described your fix.
By the way, no matter what the going EBay price is on this series of vintage
top-of-the-line Sony machines, if you need a new top-end VCR and can find
one of these excellent performers in mint operating condition that has not
be previously botch repaired with chewing gum and bailing wire or "fudge
fixed" the price could be several times higher and still be a bargain to the
well-informed critical VCR user.

 

[SHAUN]

Speaking of VCR's, I have one that will not rewind to save it's life. I was
about to junk it, but since I am in this group, I think I'll try to repair
it. With youguys help, of course!

 

[Shawn Lin]

----------------------

Shawn Lin:
Actually, what I was mostly concerned about when you described your"bending"
"fudge fix" with the pliers and vise grips....... was the proper and
critical perpendicular alignment of the capstan shaft to the deck plate as
it relates to the pinch roller and the video tape. Any significant
deviation can cause tracking and interchange problems, tape creasing, and
lots of other nasty problems...... relieving the scraping of the motor coils
was certainly a primary task that you properly identified but this is a
precision part so I cringed a little (actually I cringed a lot) when you
described your fix.
By the way, no matter what the going EBay price is on this series of vintage
top-of-the-line Sony machines, if you need a new top-end VCR and can find
one of these excellent performers in mint operating condition that has not
be previously botch repaired with chewing gum and bailing wire or "fudge
fixed" the price could be several times higher and still be a bargain to the
well-informed critical VCR user.

I understand what you're saying about the perpendicular alignment of
the capstan shaft, however, the bad bearing was allowing the capstan
to lean forward (which is how the flywheel contacts the windings in
the first place). I bent the housing in the opposite direction so
slightly that it corrected the perpendicular alignment... perhaps not
to perfection, but it is much more correct than when the flywheel was
rubbing. If you have any junk capstan motors lying around, give it a
try and you'll see it works surprisingly well as far as "fudge fixes"
go.
Anyway, the capstan motor is junk due to the damaged windings so I'm
lucky it will play and FFWD.
I used to love these vintage top-of-the-line Sony VCRs... along with
the 686HF, 585HF, I also have a pristine 595HF. At this point, I'm
just interested in liquidating them since I just bought a DVD player
with DVR. It's so much more convenient, I know I'm never looking
back. DVD recorders are just around the corner... when they drop
below the $200 mark, I'll probably have to pay someone to take these
old VCRs off my hands.

Shawn