Sansui D-90 cassette deck ff / rewind problem

Archived from groups: rec.audio.tech (More info?)

In article <7jahg05035oc1chtl69650dq4npv20nuq8@4ax.com>, Adrian
Brentnall <adrian@ambquality.co.uk> wrote:

>> Only slight snag is that the machine isn't very keen on
> fast-forwarding, and just sulks when asked to rewind tapes. Playing at
> normal speed is fine. on rewind the motor engages, then drops out
> again after a few seconds (?some kind of 'tape-not-moving' detect
> circuit?).
>
> I'm thinking that it's probably a mechanical problem - before I dive
> in there and wreck it completely - can anybody please give me some
> pointers as to what might be wrong ?

The capstan (the little silver post that moves the tape) is
normally driven by the motor from a belt. There is then a set
of rubber idlers, belts, and clutches that drive the take up and
feed reels. These things can get dirty and the rubber parts can
get hard with age. Either will cause the problem that you are
seeing.

More advanced decks have a motor that directly drives the capstan,
and a 2nd or even 3rd motor to drive the reels. You may have a
mechanical or dirt issue, but might just as likely have an
electronic problem in this case.

Dig in and see what you find.

-john-

--
====================================================================
John A. Weeks III 952-432-2708 john@johnweeks.com
Newave Communications http://www.johnweeks.com
====================================================================

Archived from groups: rec.audio.tech (More info?)

HI John

Many thanks for the reply

I took a quick look inside the mechanism last night. There is indeed a
'tape moving' detector - driven by rubber belts, and linked eventually
to the mechanical tape counter on the front panel.

I FIXED IT ! <g>
I think it was a combination of some grubbyness on the detector shaft
(which was causing the belt to slip, and the 'non-movement' to do its
job, causing the main solenoid to stop the motor) and a very 'dry'
bearing on the shaft itself which was making it more difficult for the
shaft to rotate.

Tiny amounts of cleaner and lubricant seem to have done the trick -
many thanks for the suggestions.

Regards
Adrian
Suffolk UK