Royal paper shredder

[Mark Kinsler]

Here's a good one: we have a fairly big Royal crosscut paper
shredder. The model number seems to be PCUA:16804D, which comes up as
nothing on Google. It is a nine-sheet-at-a-time crosscut shredder.
Damn thing cost fifty bucks, so it's not all that expendable.

There's a lot of circuitry inside the thing. An opto-sensor
(infrared, I think) senses when a piece of paper is inserted in the
machine and starts the motor. If the load on the motor is too great,
the motor will reverse to eject the errant glob of paper and then go
into an overload mode, which lights an indicator lamp and begins a
time delay, during which the machine is disabled. After the time
delay, the indicator light goes out and we're welcome to try again,
this time with fewer sheets of paper.

The difficulty is that the overload circuit is intermittently
paranoid. Stick a single piece of paper in the machine and the motor
starts for one second, then reverses, and the machine goes into
overload mode. It will do this repeatedly, and then inexplicably
start behaving properly. I've had some luck shutting off the power
and turning it back on, after which I jam a piece of paper into the
thing suddenly. Sometimes this startles the thing's little silicon
brain and it shreds okay for a short time, at least long enough to get
rid of the day's credit card offers.

There's at least one IC and a good deal of ancillary electronics
inside, including a thermistor to measure the motor's temperature. I
pulled this thermistor out from under the cable clamp that holds it to
the motor housing, but that didn't help. I cleaned everything that
looks like it can be cleaned.

Anyone have any ideas?

M Kinsler

[Mark Kinsler]

[Mark Kinsler]

[Mark Kinsler]

[Mark Kinsler]

[Mark Kinsler]

Well, the Earthlink server has been behaving very strangely this
evening. Sorry for the zillion multiple posts.

M Kinsler

aka Hipcrime, but with an intermittent shredder.

[Sam Goldwasser]

Detecting overload is probably monitoring motor current or some sensor on
the mechanical parts - e.g., something trips under spring pressure when it
gets stuck. Thermistor would be too slow.

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[Bushy]

Try lubricating it with silicon spray. It works better than the supplied
lubricant with my crosscut, (different brand) and is easier to apply.
Let it work in to the cutters before loading paper. Relubricate it
regularly!

Then, don't believe the manual, all the ones I've used like one or two
sheets at a time. I think they rate them like pc monitors, or they use
those smaller japanese horses!
Hope this helps,
Peter

[Terry]

Mark:
No wonder you have to shred? Four times!
Sorry but had to comment :-)

[Andrew Rossmann]

[This followup was posted to sci.electronics.repair and a copy was sent to
the cited author.]

In article <3c05c14f...@news.earthlink.net>, kin...@frognet.net
says...

> Here's a good one: we have a fairly big Royal crosscut paper
> shredder. The model number seems to be PCUA:16804D, which comes up as
> nothing on Google. It is a nine-sheet-at-a-time crosscut shredder.
> Damn thing cost fifty bucks, so it's not all that expendable.

$50 for 9-sheet crosscut?? Either you got it on sale/closeout, or it's
seriously overrated. A genuine 9-sheet cross-cut shredder should probably
cost over $200. At $50, those 9-sheets must be Kleenex.

> There's a lot of circuitry inside the thing. An opto-sensor
> (infrared, I think) senses when a piece of paper is inserted in the
> machine and starts the motor. If the load on the motor is too great,
> the motor will reverse to eject the errant glob of paper and then go
> into an overload mode, which lights an indicator lamp and begins a
> time delay, during which the machine is disabled. After the time
> delay, the indicator light goes out and we're welcome to try again,
> this time with fewer sheets of paper.
>
> The difficulty is that the overload circuit is intermittently
> paranoid. Stick a single piece of paper in the machine and the motor
> starts for one second, then reverses, and the machine goes into
> overload mode. It will do this repeatedly, and then inexplicably
> start behaving properly. I've had some luck shutting off the power
> and turning it back on, after which I jam a piece of paper into the
> thing suddenly. Sometimes this startles the thing's little silicon
> brain and it shreds okay for a short time, at least long enough to get
> rid of the day's credit card offers.

I believe most measure the current used by the motor to detect an
overload (the thermistor is just if you run it so much it starts to
overheat.) Unless there is something adjustable, about all you can do is
see if you can lubricate it to reduce friction. Check for any binding.

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[JAY RESPLER]

Mark Kinsler wrote:
>
> Here's a good one: we have a fairly big Royal crosscut paper
> shredder. The model number seems to be PCUA:16804D, which comes up as
> nothing on Google. It is a nine-sheet-at-a-time crosscut shredder.

We are Royal shredder service center. We do warranty and after
warranty repairs (on all other Royal-Olivetti products too) and
sell parts and supplies. Go here for shredder parts:

http://uweb.superlink.net/jrespler/shredder.htm

Contact us for other items.
--
Jay Respler
ADVANCED BUSINESS MACHINES CO.
--
JRes...@superlink.net
SKY VIEWS: http://mars.superlink.net/jrespler/skyviews.htm
Satellite Tracker * Early Typewriter Collector
Freehold, New Jersey

[JJS]

Maybe you are seeing the early symptons of a power supply about to fail.
Last month, I repaired a friend's Royal paper shredder that was blowing its
fuse as soon as it was turned on. I do not remember the model number, but
your shredder sounds quite similar. In my case, the problem turned out to
be a shorted diode on the DC power supply for the motor. The power supply
is very crude - just 4 diodes without any filtering to create full rectified
120V DC for the shredder motor. Testing the diodes in both directions with
a DVM located the bad 6A4 diode.

John Smith
jj...@earthlink.net
"Mark Kinsler" <kin...@frognet.net> wrote in message
news:3c05ac55...@news.earthlink.net...

[Jerry Greenberg]

kin...@frognet.net (Mark Kinsler) wrote in message news:<3c05ac55...@news.earthlink.net>...

It sounds like an overload condition. This can be a defect in the
motor, or one or some of the driver components to the motor may be
defective.

For $50 I would go and get a new one. The time and cost of parts
involved are not worth it. Infact in most of these items, the
manufactures are not even setup to supply parts. They will tell you
that the service cost is too high, and the unit should be completely
replaced.

Jerry Greenberg
http://www.zoom-one.com

--