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Paper Shredder problem with paper detect circuitry

F

Father Guido

Jan 1, 1970
0
Hi,

I have a Royal 80MX paper shredder that won't shred (go forward), it
goes backwards fine so the motor etc. are working OK. This just
happened suddenly last week. It's as if the paper detection circuit
doesn't recognize paper being inserted. I took it apart and their is a
small plug in connector on the main circuit board with 4 wires leading
to a small trianglular shaped component (numbered only 0321, which may
be a date code for all I know) with two wires going to each of what
looks like 2 small blue plastic lenses. I assume that when paper is
inserted a circuit (of light?) is broken telling the machine to turn
on and shred in automatic mode. I found nothing on the other side of
the paper entrance, so maybe it bounces light off of the chromed
roller. Anyway, getting a replacement part will be impossible, but...
if I knew how this actually worked I could maybe short out the sockets
on the main board to make it think/detect there is always paper in it
so it would always work, then I could just turn it off to stop it, and
turn it on when I wanted to shred.

Any thoughts?

TIA!

Norm
 
J

James Sweet

Jan 1, 1970
0
Father said:
Hi,

I have a Royal 80MX paper shredder that won't shred (go forward), it
goes backwards fine so the motor etc. are working OK. This just
happened suddenly last week. It's as if the paper detection circuit
doesn't recognize paper being inserted. I took it apart and their is a
small plug in connector on the main circuit board with 4 wires leading
to a small trianglular shaped component (numbered only 0321, which may
be a date code for all I know) with two wires going to each of what
looks like 2 small blue plastic lenses. I assume that when paper is
inserted a circuit (of light?) is broken telling the machine to turn
on and shred in automatic mode. I found nothing on the other side of
the paper entrance, so maybe it bounces light off of the chromed
roller. Anyway, getting a replacement part will be impossible, but...
if I knew how this actually worked I could maybe short out the sockets
on the main board to make it think/detect there is always paper in it
so it would always work, then I could just turn it off to stop it, and
turn it on when I wanted to shred.

Any thoughts?

TIA!

Norm


It's a reflective optical sensor. Nothing more than an infra-red LED and
a photodiode or phototransistor. If you have a CCD camera (webcam,
camcorder, etc) you should be able to see the IR from the LED if it's
working. Shorting across the phototransistor should activate the motor.

It may not be the sensor though, sometimes reverse is accomplished
entirely through the mechanical switch, while forward is triggered by
the electronics. Watch your fingers while working on these things.
 
F

Father Guido

Jan 1, 1970
0
It's a reflective optical sensor. Nothing more than an infra-red LED and
a photodiode or phototransistor. If you have a CCD camera (webcam,
camcorder, etc) you should be able to see the IR from the LED if it's
working. Shorting across the phototransistor should activate the motor.

It may not be the sensor though, sometimes reverse is accomplished
entirely through the mechanical switch, while forward is triggered by
the electronics. Watch your fingers while working on these things.

Thanks James, I will give shorting a shot since I have nothing to
lose. First I will try looking at the sensor in action with thru my
digital camera.

Thanks!
 
F

Father Guido

Jan 1, 1970
0
So there is a manual reverse switch but no manual forward?

It has a REV OFF AUTO switch. I am assuming that if I can fake the
paper sensor into working (all the time) I could leave the shredder in
OFF position, and shred (continuously) when I put the shredder into
AUTO, then just put to OFF when finished. No more autofeed, just
straight OFF and continuous ON (in auto switch loaction). For all the
shredding I do just having the equivalent to a manual REV OFF FWD is
all I need. Actually I already bought a bigger shredder, but if I can
fix it I can give it to my daughter instead of the dump. :)
You could try shorting different pairs of wires that go to the sensor
together. They are very low voltage/current and you've got nothing to
lose if you aren't trying to repair it correctly. You could also try to
determine the voltage/current requirements of the motor and rig up some
external supply. Lost of things you could experiment with, just depends on
your level of curiosity and ambition.

Apparently parts are very hard to come by, especially for a machine
several years old. If I break it, I break it. I have nothing to lose.

Thanks for your help.

Norm
 
G

GMAN

Jan 1, 1970
0
It has a REV OFF AUTO switch. I am assuming that if I can fake the
paper sensor into working (all the time) I could leave the shredder in
OFF position, and shred (continuously) when I put the shredder into
AUTO, then just put to OFF when finished. No more autofeed, just
straight OFF and continuous ON (in auto switch loaction). For all the
shredding I do just having the equivalent to a manual REV OFF FWD is
all I need. Actually I already bought a bigger shredder, but if I can
fix it I can give it to my daughter instead of the dump. :)

Apparently parts are very hard to come by, especially for a machine
several years old. If I break it, I break it. I have nothing to lose.

Thanks for your help.

Norm

You dont want a continous ON. It can overheat the motor and burn down your
home, business etc...
 
F

Father Guido

Jan 1, 1970
0
You dont want a continous ON. It can overheat the motor and burn down your
home, business etc...

Continuous on when NOT turned off, in otherwords it'll be on or off,
no more automatic. When I need to shred I'll turn the machine on, then
I'll turn it off. Just can't leave it in auto so I can just insert a
page whenever and have it swallow.
 
F

Father Guido

Jan 1, 1970
0
It's a reflective optical sensor. Nothing more than an infra-red LED and
a photodiode or phototransistor. If you have a CCD camera (webcam,
camcorder, etc) you should be able to see the IR from the LED if it's
working. Shorting across the phototransistor should activate the motor.

I hooked up the paper sensor again and looked at it thru my camera, I
can definitely see the I-R LED lighting up. So, I tried shorting the
opposite pair to the side that I thought lit up, but nothing happened.
Since I had nothing to lose I shorted the other pair, BINGO, the
shredder works in AUTO (as if manual FWD) and REV, but not automatic,
and the cutters don't run continuously either in any switch position.
So I have all manual control, FWD, OFF, REV. Ceh la vie, at least it's
useable this way. Thanks for everyones help!
 
B

b

Jan 1, 1970
0
You dont want a continous ON. It can overheat the motor and burn down your
home, business etc...

maybe add a mechanical microwave timer to limit the 'on' time?!
You see so many dumped microwaves , shame not to make use of some of
those parts!
-B
 
R

Ross Herbert

Jan 1, 1970
0
:Hi,
:
:I have a Royal 80MX paper shredder that won't shred (go forward), it
:goes backwards fine so the motor etc. are working OK. This just
:happened suddenly last week. It's as if the paper detection circuit
:doesn't recognize paper being inserted. I took it apart and their is a
:small plug in connector on the main circuit board with 4 wires leading
:to a small trianglular shaped component (numbered only 0321, which may
:be a date code for all I know) with two wires going to each of what
:looks like 2 small blue plastic lenses. I assume that when paper is
:inserted a circuit (of light?) is broken telling the machine to turn
:eek:n and shred in automatic mode. I found nothing on the other side of
:the paper entrance, so maybe it bounces light off of the chromed
:roller. Anyway, getting a replacement part will be impossible, but...
:if I knew how this actually worked I could maybe short out the sockets
:eek:n the main board to make it think/detect there is always paper in it
:so it would always work, then I could just turn it off to stop it, and
:turn it on when I wanted to shred.
:
:Any thoughts?
:
:TIA!
:
:Norm


Usually, reversing a shredder is independant of the paper sensor. The paper
sensor only detects whether paper is inserted for shredding and the motor always
goes forward automatically. Only on paper jams does the motor need to reverse,
and that is accomplished by a manually operated reversing switch. That's how it
works on my old Fordigraph 100 Auto anyway.
 
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