optical mouse malfunction
 

Using WinXP and Contour USB optical mouse. Today, several times the cursor
didn't move when I moved the mouse; then it would start up again. Finally,
Windows informed me that a USB device was malfunctioning and I should try
another port or another device. I plugged in another mouse, and it's working
fine. The Contour mouse is expensive to replace (around $110), so it's a
good thing I had an extra one in my office. My question: Are optical mice
fixable, or should I just toss it?

Thank you!

Jo-Anne

optical mouse malfunction
 

Jo-Anne wrote:
Using WinXP and Contour USB optical mouse. Today, several times the cursor
didn't move when I moved the mouse; then it would start up again. Finally,
Windows informed me that a USB device was malfunctioning and I should try
another port or another device. I plugged in another mouse, and it's working
fine. The Contour mouse is expensive to replace (around $110), so it's a
good thing I had an extra one in my office. My question: Are optical mice
fixable, or should I just toss it?

Thank you!

Jo-Anne



As a "broken wire specialist" :-) I would remove the screws
from the mouse, and examine the condition of the wires where they
connect to the mouse PCB. Sometimes the broken wire, is in
an insulated section of the wire (like where the wire passes
through the mouse casing).

To repair broken wires, you undo the "knot" in the wire, which
functions as strain relief, cut about three inches of wire off the end,
strip and prep the wire ends and connect them to the mouse PCB. This
procedure can be repeated until the wire is quite short. Replace the
knot as well, so the mouse continues to have strain relief. Some
mice have plastic posts, and a torturous path the wire feeds
through, which performs the same function as a knot in the wire.
The strain relief, prevents exterior stress, from getting to
pull the wires away from the PCB.

(This is almost as much fun, as fixing the wiring in a Weed Wacker.
Which I have also done.)

Take note of the wire colors, and make a diagram of wire color
versus which hole in the PCB they go into.

Occasionally, an optical mouse has a failure in the optical sensor.
I have no idea how you diagnose things at that level of detail.
As I'm a "broken wire specialist".

The sensor is actually more complicated than you'd think. I think
it has a matrix of detection elements. And the sensor chip may
do some kind of analysis to determine movement. It's more than
a simple photodetector. When you look inside, you'll see a
plastic lens assembly, over top of the sensor chip.

http://en.wikipedia.org/wiki/Optical_mouse

"Optical mice capture one thousand successive images or more per
second. Depending on how fast the mouse is moving, each image will
be offset from the previous one by a fraction of a pixel or as many
as several pixels. Optical mice mathematically process these images
using cross correlation to calculate how much each successive image
is offset from the previous one.

An optical mouse might use an image sensor having an 18 × 18 pixel
array of monochromatic pixels. Its sensor would normally share the
same ASIC as that used for storing and processing the images. One
refinement would be accelerating the correlation process by using
information from previous motions, and another refinement would be
preventing deadbands when moving slowly by adding interpolation or
frame-skipping."

It can probably still function, with dirt on the lens. But a
completely dead sensor, is a completely dead sensor.

Check your wires first. Using an ohmmeter, you can buzz from
USB connector to the pad on the PCB, and prove each wire on the
mouse is intact. It can be difficult to detect a wire which
is intermittent, and get it to open circuit at the same time
as you're measuring it.

The idea is, if you're lucky, removing the screws and doing
a visual inspection, tells you all you need to know. If you're
really lucky, the wire will visually tell you, the break is
inside a certain section. But sometimes, you just have to
"give it a trim" and snip off the three inches of wire and
re-terminate.

And it's pretty hard to repair something like this, without
tools such as your "trusty" soldering iron. The burn mark on
my finger is just about healed now. I only lost a little bit
of nerve sensitivity.

HTH,
Paul

optical mouse malfunction
 

"Paul" wrote in message
...
Jo-Anne wrote:
Using WinXP and Contour USB optical mouse. Today, several times the
cursor didn't move when I moved the mouse; then it would start up again.
Finally, Windows informed me that a USB device was malfunctioning and I
should try another port or another device. I plugged in another mouse,
and it's working fine. The Contour mouse is expensive to replace (around
$110), so it's a good thing I had an extra one in my office. My question:
Are optical mice fixable, or should I just toss it?

Thank you!

Jo-Anne

As a "broken wire specialist" :-) I would remove the screws
from the mouse, and examine the condition of the wires where they
connect to the mouse PCB. Sometimes the broken wire, is in
an insulated section of the wire (like where the wire passes
through the mouse casing).

To repair broken wires, you undo the "knot" in the wire, which
functions as strain relief, cut about three inches of wire off the end,
strip and prep the wire ends and connect them to the mouse PCB. This
procedure can be repeated until the wire is quite short. Replace the
knot as well, so the mouse continues to have strain relief. Some
mice have plastic posts, and a torturous path the wire feeds
through, which performs the same function as a knot in the wire.
The strain relief, prevents exterior stress, from getting to
pull the wires away from the PCB.

(This is almost as much fun, as fixing the wiring in a Weed Wacker.
Which I have also done.)

Take note of the wire colors, and make a diagram of wire color
versus which hole in the PCB they go into.

Occasionally, an optical mouse has a failure in the optical sensor.
I have no idea how you diagnose things at that level of detail.
As I'm a "broken wire specialist".

The sensor is actually more complicated than you'd think. I think
it has a matrix of detection elements. And the sensor chip may
do some kind of analysis to determine movement. It's more than
a simple photodetector. When you look inside, you'll see a
plastic lens assembly, over top of the sensor chip.

http://en.wikipedia.org/wiki/Optical_mouse

"Optical mice capture one thousand successive images or more per
second. Depending on how fast the mouse is moving, each image will
be offset from the previous one by a fraction of a pixel or as many
as several pixels. Optical mice mathematically process these images
using cross correlation to calculate how much each successive image
is offset from the previous one.

An optical mouse might use an image sensor having an 18 × 18 pixel
array of monochromatic pixels. Its sensor would normally share the
same ASIC as that used for storing and processing the images. One
refinement would be accelerating the correlation process by using
information from previous motions, and another refinement would be
preventing deadbands when moving slowly by adding interpolation or
frame-skipping."

It can probably still function, with dirt on the lens. But a
completely dead sensor, is a completely dead sensor.

Check your wires first. Using an ohmmeter, you can buzz from
USB connector to the pad on the PCB, and prove each wire on the
mouse is intact. It can be difficult to detect a wire which
is intermittent, and get it to open circuit at the same time
as you're measuring it.

The idea is, if you're lucky, removing the screws and doing
a visual inspection, tells you all you need to know. If you're
really lucky, the wire will visually tell you, the break is
inside a certain section. But sometimes, you just have to
"give it a trim" and snip off the three inches of wire and
re-terminate.

And it's pretty hard to repair something like this, without
tools such as your "trusty" soldering iron. The burn mark on
my finger is just about healed now. I only lost a little bit
of nerve sensitivity.

HTH,
Paul


Thank you, Paul! My husband is the wire repairperson in our household. He
managed to fix our old hair dryer when one wire broke, and now he's about to
fix the other wire. So I'll definitely give him this post.

Jo-Anne

optical mouse malfunction
 

Jo-Anne wrote:

Using WinXP and Contour USB optical mouse. Today, several times the cursor
didn't move when I moved the mouse; then it would start up again. Finally,
Windows informed me that a USB device was malfunctioning and I should try
another port or another device. I plugged in another mouse, and it's working
fine. The Contour mouse is expensive to replace (around $110), so it's a
good thing I had an extra one in my office. My question: Are optical mice
fixable, or should I just toss it?

Did you use a penlight and tweezers to clean out the hair, dust, lint,
and other crap that has gotten in front of the LED/laser?

I've had a single hair (so thin I couldn't see it with my naked eye
until I hit it with a light to change the angle of reflection of the
light off the hair) that cause erratic movement of the mouse. The hair
would jitter about, the sensor saw that movement and thought it was the
pad moving, and the mouse cursor would lag, jitter, or suddenly bounce
to somewhere quite a ways from the current position. If enough crap
gets in front of the sensor, it's not going to see that the mouse is
moving (the crap is moving with the mouse).

optical mouse malfunction
 

"VanguardLH" wrote in message
...
Jo-Anne wrote:

Using WinXP and Contour USB optical mouse. Today, several times the
cursor
didn't move when I moved the mouse; then it would start up again.
Finally,
Windows informed me that a USB device was malfunctioning and I should try
another port or another device. I plugged in another mouse, and it's
working
fine. The Contour mouse is expensive to replace (around $110), so it's a
good thing I had an extra one in my office. My question: Are optical mice
fixable, or should I just toss it?

Did you use a penlight and tweezers to clean out the hair, dust, lint,
and other crap that has gotten in front of the LED/laser?

I've had a single hair (so thin I couldn't see it with my naked eye
until I hit it with a light to change the angle of reflection of the
light off the hair) that cause erratic movement of the mouse. The hair
would jitter about, the sensor saw that movement and thought it was the
pad moving, and the mouse cursor would lag, jitter, or suddenly bounce
to somewhere quite a ways from the current position. If enough crap
gets in front of the sensor, it's not going to see that the mouse is
moving (the crap is moving with the mouse).

Thank you, Vanguard! My husband just tried that at your suggestion--but no
luck. Windows won't even recognize the mouse any more. Good thing to check
in the future, though, if I observe any erratic mouse behavior. In the
meantime, my husband is going to try to take the mouse apart (tricky, since
there are no obvious screws).

Jo-Anne

optical mouse malfunction
 

Jo-Anne wrote:

my husband is going to try to take the mouse apart (tricky, since
there are no obvious screws).

They're under the slider feet. Once you peel them off, you'll need
something to glue them back on. I have seen the teflon mouse feet for
sale but you'll probably have to trim them to fit the recess in the
mouse base.

Some mouse shells snap together - and aren't designed to snap apart.
that is, when you flex the upper shell trying to dislodge it from the
fingers in the lower shell, you could break the fingers so the shell
halves won't snap together again. That's when hot-melt glue or epoxy
comes in. Many times you can't figure out how the shell halves snap
together until you break it apart and then it's too late.

If it's a wireless mouse, sometimes the retaining screw is in the
battery compartment. Remove the batteries and check. If it's there,
after removing the screw, the shell halves should slide together at a
slight angle out of the retaining grooves.

Although you said it is a USB mouse, that doesn't say if it is wired or
wireless. You have already tried putting fresh batteries in to the
mouse case, right?

So when the hubby figures he can't find any obvious loose or broken
chips, wires, or other mechanical defect, you won't be barking at him
for breaking your mouse beyond expert repair, right?

optical mouse malfunction
 

VanguardLH wrote:

Although you said it is a USB mouse, that doesn't say if it is wired or
wireless. You have already tried putting fresh batteries in to the
mouse case, right?

Um, by the way, if it's a wireless mouse, you did check the on/off
switch under the mouse or in the battery compartment or wherever it is
is in the ON position, right? For wireless mice, check the batteries
are good and check the mouse is switched on. Some mice have an on/off
switch to conserve on power when they're not used for awhile and the
low-power state still consumes power.

optical mouse malfunction
 

Jo-Anne wrote:
"VanguardLH" wrote in message
...
Jo-Anne wrote:

Using WinXP and Contour USB optical mouse. Today, several times the
cursor
didn't move when I moved the mouse; then it would start up again.
Finally,
Windows informed me that a USB device was malfunctioning and I should try
another port or another device. I plugged in another mouse, and it's
working
fine. The Contour mouse is expensive to replace (around $110), so it's a
good thing I had an extra one in my office. My question: Are optical mice
fixable, or should I just toss it?
Did you use a penlight and tweezers to clean out the hair, dust, lint,
and other crap that has gotten in front of the LED/laser?

I've had a single hair (so thin I couldn't see it with my naked eye
until I hit it with a light to change the angle of reflection of the
light off the hair) that cause erratic movement of the mouse. The hair
would jitter about, the sensor saw that movement and thought it was the
pad moving, and the mouse cursor would lag, jitter, or suddenly bounce
to somewhere quite a ways from the current position. If enough crap
gets in front of the sensor, it's not going to see that the mouse is
moving (the crap is moving with the mouse).

Thank you, Vanguard! My husband just tried that at your suggestion--but no
luck. Windows won't even recognize the mouse any more. Good thing to check
in the future, though, if I observe any erratic mouse behavior. In the
meantime, my husband is going to try to take the mouse apart (tricky, since
there are no obvious screws).

Jo-Anne

The screw or screws can be cleverly hidden.

My newer mice, tend to be "one screw" designs, where the screw
is underneath a sticker. On some mice, the sticker must be defaced,
to get in. On other mice, the sticker has an "X" shaped cut, so as
soon as you push a Philips head screwdriver in there, the sticker parts
and lets the screwdriver pass. The purpose of the sticker is for
"warranty is void" detection.

You can try sweeping the base of the mouse with a powerful magnet,
but in addition to detecting the screw, you'll also get false
positives from other metal inside. That might give a hint as
to where it's hiding.

There are always electronics out there, completely sealed and
meant to be annoying. When my favorite computer speaker
needed to be repaired, it was glued plastic. I took a hacksaw,
and cut a slot in the top of the speaker. And that gave enough
room, to insert a tool and "pry" the rest of the speaker halves
apart. Speaker amp had a dry solder joint, which was easily
repaired. Speaker looks like hell, but it still works!

Paul

optical mouse malfunction
 

"VanguardLH" wrote in message
...
Jo-Anne wrote:

my husband is going to try to take the mouse apart (tricky, since
there are no obvious screws).

They're under the slider feet. Once you peel them off, you'll need
something to glue them back on. I have seen the teflon mouse feet for
sale but you'll probably have to trim them to fit the recess in the
mouse base.

Some mouse shells snap together - and aren't designed to snap apart.
that is, when you flex the upper shell trying to dislodge it from the
fingers in the lower shell, you could break the fingers so the shell
halves won't snap together again. That's when hot-melt glue or epoxy
comes in. Many times you can't figure out how the shell halves snap
together until you break it apart and then it's too late.

If it's a wireless mouse, sometimes the retaining screw is in the
battery compartment. Remove the batteries and check. If it's there,
after removing the screw, the shell halves should slide together at a
slight angle out of the retaining grooves.

Although you said it is a USB mouse, that doesn't say if it is wired or
wireless. You have already tried putting fresh batteries in to the
mouse case, right?

So when the hubby figures he can't find any obvious loose or broken
chips, wires, or other mechanical defect, you won't be barking at him
for breaking your mouse beyond expert repair, right?


Thank you again, Vanguard! It's a wired mouse, so no batteries. I certainly
won't complain if it can't be fixed, but it should be interesting to
try...or at least to see what's inside.

Jo-Anne

optical mouse malfunction
 

"Paul" wrote in message
...
Jo-Anne wrote:
"VanguardLH" wrote in message
...
Jo-Anne wrote:

Using WinXP and Contour USB optical mouse. Today, several times the
cursor
didn't move when I moved the mouse; then it would start up again.
Finally,
Windows informed me that a USB device was malfunctioning and I should
try
another port or another device. I plugged in another mouse, and it's
working
fine. The Contour mouse is expensive to replace (around $110), so it's
a
good thing I had an extra one in my office. My question: Are optical
mice
fixable, or should I just toss it?
Did you use a penlight and tweezers to clean out the hair, dust, lint,
and other crap that has gotten in front of the LED/laser?

I've had a single hair (so thin I couldn't see it with my naked eye
until I hit it with a light to change the angle of reflection of the
light off the hair) that cause erratic movement of the mouse. The hair
would jitter about, the sensor saw that movement and thought it was the
pad moving, and the mouse cursor would lag, jitter, or suddenly bounce
to somewhere quite a ways from the current position. If enough crap
gets in front of the sensor, it's not going to see that the mouse is
moving (the crap is moving with the mouse).

Thank you, Vanguard! My husband just tried that at your suggestion--but
no luck. Windows won't even recognize the mouse any more. Good thing to
check in the future, though, if I observe any erratic mouse behavior. In
the meantime, my husband is going to try to take the mouse apart (tricky,
since there are no obvious screws).

Jo-Anne

The screw or screws can be cleverly hidden.

My newer mice, tend to be "one screw" designs, where the screw
is underneath a sticker. On some mice, the sticker must be defaced,
to get in. On other mice, the sticker has an "X" shaped cut, so as
soon as you push a Philips head screwdriver in there, the sticker parts
and lets the screwdriver pass. The purpose of the sticker is for
"warranty is void" detection.

You can try sweeping the base of the mouse with a powerful magnet,
but in addition to detecting the screw, you'll also get false
positives from other metal inside. That might give a hint as
to where it's hiding.

There are always electronics out there, completely sealed and
meant to be annoying. When my favorite computer speaker
needed to be repaired, it was glued plastic. I took a hacksaw,
and cut a slot in the top of the speaker. And that gave enough
room, to insert a tool and "pry" the rest of the speaker halves
apart. Speaker amp had a dry solder joint, which was easily
repaired. Speaker looks like hell, but it still works!

Paul


Thank you again, Paul! I'll report back on what, if anything, worked.

Jo-Anne

optical mouse malfunction
 

On 03/07/2012 21:32, Jo-Anne wrote:
Using WinXP and Contour USB optical mouse. Today, several times the cursor
didn't move when I moved the mouse; then it would start up again. Finally,
Windows informed me that a USB device was malfunctioning and I should try
another port or another device. I plugged in another mouse, and it's working
fine. The Contour mouse is expensive to replace (around $110), so it's a
good thing I had an extra one in my office. My question: Are optical mice
fixable, or should I just toss it?

Thank you!

Jo-Anne




The short answer is optical mice are NOT fixable. However, you paid
$110 for a mouse so it must be some extra special one. What exactly
does it do that my $3.99 mice can't do?

I always but cheaper ones so that if they are broken or "walked away"
from my desk then I won't have sleepless nights.

--
Good Guy
Website: http://mytaxsite.co.uk
Website: http://html-css.co.uk
Forums: http://mytaxsite.boardhost.com
Email: http://mytaxsite.co.uk/contact-us

optical mouse malfunction
 

"Good Guy" wrote in message
...
On 03/07/2012 21:32, Jo-Anne wrote:
Using WinXP and Contour USB optical mouse. Today, several times the
cursor
didn't move when I moved the mouse; then it would start up again.
Finally,
Windows informed me that a USB device was malfunctioning and I should try
another port or another device. I plugged in another mouse, and it's
working
fine. The Contour mouse is expensive to replace (around $110), so it's a
good thing I had an extra one in my office. My question: Are optical mice
fixable, or should I just toss it?

Thank you!

Jo-Anne

The short answer is optical mice are NOT fixable. However, you paid $110
for a mouse so it must be some extra special one. What exactly does it do
that my $3.99 mice can't do?

I always but cheaper ones so that if they are broken or "walked away" from
my desk then I won't have sleepless nights.
--
Good Guy
Website: http://mytaxsite.co.uk
Website: http://html-css.co.uk
Forums: http://mytaxsite.boardhost.com
Email: http://mytaxsite.co.uk/contact-us


It comes in several sizes, in versions for the left hand as well as the
right, has three real buttons as well as a scroll wheel, has a thumb rest,
is super-comfortable to use (I can use it for hours without my hand or arm
getting tired), and has worked well for several years. I like it so much
that if my newer one breaks (I bought two at the same time--for much less
than the current price), I'll fork out the money for another. Since I don't
work in an office with other people, I don't have to worry about my
expensive mouse walking away.

You can learn about this mouse at
http://ergo.contour-design.com/products/contour-mouse, but only by trying it
would you know if it's the best mouse for your hand--and I don't know of any
retailer that carries it (probably because it's so expensive). I tried a lot
of different mice at various stores and couldn't find any that were anywhere
near as comfortable as this one for me. The little Logitech mouse I use with
my netbook when I travel is downright UNcomfortable.

Jo-Anne

optical mouse malfunction
 

"Paul" wrote in message
...
Jo-Anne wrote:
Using WinXP and Contour USB optical mouse. Today, several times the
cursor didn't move when I moved the mouse; then it would start up again.
Finally, Windows informed me that a USB device was malfunctioning and I
should try another port or another device. I plugged in another mouse,
and it's working fine. The Contour mouse is expensive to replace (around
$110), so it's a good thing I had an extra one in my office. My question:
Are optical mice fixable, or should I just toss it?

Thank you!

Jo-Anne

As a "broken wire specialist" :-) I would remove the screws
from the mouse, and examine the condition of the wires where they
connect to the mouse PCB. Sometimes the broken wire, is in
an insulated section of the wire (like where the wire passes
through the mouse casing).

To repair broken wires, you undo the "knot" in the wire, which
functions as strain relief, cut about three inches of wire off the end,
strip and prep the wire ends and connect them to the mouse PCB. This
procedure can be repeated until the wire is quite short. Replace the
knot as well, so the mouse continues to have strain relief. Some
mice have plastic posts, and a torturous path the wire feeds
through, which performs the same function as a knot in the wire.
The strain relief, prevents exterior stress, from getting to
pull the wires away from the PCB.

(This is almost as much fun, as fixing the wiring in a Weed Wacker.
Which I have also done.)

Take note of the wire colors, and make a diagram of wire color
versus which hole in the PCB they go into.

Occasionally, an optical mouse has a failure in the optical sensor.
I have no idea how you diagnose things at that level of detail.
As I'm a "broken wire specialist".

The sensor is actually more complicated than you'd think. I think
it has a matrix of detection elements. And the sensor chip may
do some kind of analysis to determine movement. It's more than
a simple photodetector. When you look inside, you'll see a
plastic lens assembly, over top of the sensor chip.

http://en.wikipedia.org/wiki/Optical_mouse

"Optical mice capture one thousand successive images or more per
second. Depending on how fast the mouse is moving, each image will
be offset from the previous one by a fraction of a pixel or as many
as several pixels. Optical mice mathematically process these images
using cross correlation to calculate how much each successive image
is offset from the previous one.

An optical mouse might use an image sensor having an 18 × 18 pixel
array of monochromatic pixels. Its sensor would normally share the
same ASIC as that used for storing and processing the images. One
refinement would be accelerating the correlation process by using
information from previous motions, and another refinement would be
preventing deadbands when moving slowly by adding interpolation or
frame-skipping."

It can probably still function, with dirt on the lens. But a
completely dead sensor, is a completely dead sensor.

Check your wires first. Using an ohmmeter, you can buzz from
USB connector to the pad on the PCB, and prove each wire on the
mouse is intact. It can be difficult to detect a wire which
is intermittent, and get it to open circuit at the same time
as you're measuring it.

The idea is, if you're lucky, removing the screws and doing
a visual inspection, tells you all you need to know. If you're
really lucky, the wire will visually tell you, the break is
inside a certain section. But sometimes, you just have to
"give it a trim" and snip off the three inches of wire and
re-terminate.

And it's pretty hard to repair something like this, without
tools such as your "trusty" soldering iron. The burn mark on
my finger is just about healed now. I only lost a little bit
of nerve sensitivity.

HTH,
Paul

You were right, Paul--it's a broken wire. Unfortunately, the mouse may be
TOO well made. There are five wires in a cord or sleeve (not sure what to
call it); and at the mouse end, besides their being taped together and to
the sleeve, each wire is crimped into a separate hole in a plastic piece. I
suspect they'd all have to be carefully taken out of that piece, cut far
enough back to get past the break in the one wire, wherever it is, and then
recrimped (assuming the plastic piece survives). Moreover, there's a plastic
"buffering" piece on the outside of the sleeve at the entryway to the mouse,
and it doesn't come off. I'm very tempted to write to the company to ask if
it can sell me another cord...

Jo-Anne

optical mouse malfunction
 

"VanguardLH" wrote in message
...
Jo-Anne wrote:

my husband is going to try to take the mouse apart (tricky, since
there are no obvious screws).

They're under the slider feet. Once you peel them off, you'll need
something to glue them back on. I have seen the teflon mouse feet for
sale but you'll probably have to trim them to fit the recess in the
mouse base.


They (three of them) were indeed under the slider feet, Vanguard. Thank you!
As I just posted to Paul, one of five wires is broken, but given the setup
of the cord or sleeve it might be impossible to fix it.

Jo-Anne

optical mouse malfunction
 

Jo-Anne wrote:

"Paul" wrote in message
...
Jo-Anne wrote:
Using WinXP and Contour USB optical mouse. Today, several times the
cursor didn't move when I moved the mouse; then it would start up again.
Finally, Windows informed me that a USB device was malfunctioning and I
should try another port or another device. I plugged in another mouse,
and it's working fine. The Contour mouse is expensive to replace (around
$110), so it's a good thing I had an extra one in my office. My question:
Are optical mice fixable, or should I just toss it?

Thank you!

Jo-Anne

As a "broken wire specialist" :-) I would remove the screws
from the mouse, and examine the condition of the wires where they
connect to the mouse PCB. Sometimes the broken wire, is in
an insulated section of the wire (like where the wire passes
through the mouse casing).

To repair broken wires, you undo the "knot" in the wire, which
functions as strain relief, cut about three inches of wire off the end,
strip and prep the wire ends and connect them to the mouse PCB. This
procedure can be repeated until the wire is quite short. Replace the
knot as well, so the mouse continues to have strain relief. Some
mice have plastic posts, and a torturous path the wire feeds
through, which performs the same function as a knot in the wire.
The strain relief, prevents exterior stress, from getting to
pull the wires away from the PCB.

(This is almost as much fun, as fixing the wiring in a Weed Wacker.
Which I have also done.)

Take note of the wire colors, and make a diagram of wire color
versus which hole in the PCB they go into.

Occasionally, an optical mouse has a failure in the optical sensor.
I have no idea how you diagnose things at that level of detail.
As I'm a "broken wire specialist".

The sensor is actually more complicated than you'd think. I think
it has a matrix of detection elements. And the sensor chip may
do some kind of analysis to determine movement. It's more than
a simple photodetector. When you look inside, you'll see a
plastic lens assembly, over top of the sensor chip.

http://en.wikipedia.org/wiki/Optical_mouse

"Optical mice capture one thousand successive images or more per
second. Depending on how fast the mouse is moving, each image will
be offset from the previous one by a fraction of a pixel or as many
as several pixels. Optical mice mathematically process these images
using cross correlation to calculate how much each successive image
is offset from the previous one.

An optical mouse might use an image sensor having an 18 × 18 pixel
array of monochromatic pixels. Its sensor would normally share the
same ASIC as that used for storing and processing the images. One
refinement would be accelerating the correlation process by using
information from previous motions, and another refinement would be
preventing deadbands when moving slowly by adding interpolation or
frame-skipping."

It can probably still function, with dirt on the lens. But a
completely dead sensor, is a completely dead sensor.

Check your wires first. Using an ohmmeter, you can buzz from
USB connector to the pad on the PCB, and prove each wire on the
mouse is intact. It can be difficult to detect a wire which
is intermittent, and get it to open circuit at the same time
as you're measuring it.

The idea is, if you're lucky, removing the screws and doing
a visual inspection, tells you all you need to know. If you're
really lucky, the wire will visually tell you, the break is
inside a certain section. But sometimes, you just have to
"give it a trim" and snip off the three inches of wire and
re-terminate.

And it's pretty hard to repair something like this, without
tools such as your "trusty" soldering iron. The burn mark on
my finger is just about healed now. I only lost a little bit
of nerve sensitivity.

HTH,
Paul

You were right, Paul--it's a broken wire. Unfortunately, the mouse may be
TOO well made. There are five wires in a cord or sleeve (not sure what to
call it); and at the mouse end, besides their being taped together and to
the sleeve, each wire is crimped into a separate hole in a plastic piece. I
suspect they'd all have to be carefully taken out of that piece, cut far
enough back to get past the break in the one wire, wherever it is, and then
recrimped (assuming the plastic piece survives). Moreover, there's a plastic
"buffering" piece on the outside of the sleeve at the entryway to the mouse,
and it doesn't come off. I'm very tempted to write to the company to ask if
it can sell me another cord...

Jo-Anne

A picture posted online somewhere and given a link here would better
help for others to know what you're trying to describe.