Introduction: Silent Optical Mouse (No Red Shining Light)
So, i got a new computer and i use it as an HTPC and home server, it sits nicely in my room and it's up and running all day 24/7, even when i'm trying to sleep so any bright light will disturb my dreams.
The only light on the PC is the power light and the HDD light, the power LED isn't too bright, the same for the LCD monitor and the HDD led is in the back of the PC case, the keyboard leds can be easily turned off so it isn't an issue. Now the real problem comes with the optical mice included in the PC. My older mouse will get bored of being red-shiny all time and will turn off but this new mouse won't, it keeps shining bright red light all over the desktop all night long.
Something has to be done...
The goals to this instructables are:
Kill the red light.
Keep the mouse aestetics nice and unscratched, since it's brand new and good looking.
Same or better functionality.
No analogic/mechanical electronics involved (forget about putting a switch or anything like that).
Well, the goal was achieved very easily and with a very few tools.
I'll show you on the next step.
Step 1: Testing, Testing, 1, 2...
Tools and materials:
-Small philips screwdrivers
-Soldering iron
-Some flux and solder wire
-Cutting pliers
-875nm Infrared LED
The specification sheet of various optical sensors for mouses say that it can work with no problem using infrared light, but not all sensors are the same so, first, you need to make sure that the particular one you have, can move on IR light, to test this, go get your IR TV remote and turn off the lights, (the HT, sat or audio remote will work too as long as it uses IR Light and has enough batteries) point it to the optical sensor of the mouse and press a key on the remote, keep it pressed and see if the mouse reacts to the invisible light, you can be aware of this because of the change in intensity of the LED inside the mouse or by the cursor moving on the computer screen.
If the mouse reacts fine, then go ahead and try the next step, if it doesn't do anything, you can't modify your mouse using this method.
Step 2: Taking It Apart!
To continue, you need to take apart your mouse, find the screws that can be hiding under one of the labels on the bottom and remove the top cover.
To remove the top cover, lift the part on the opposite side of the cable and slide until it unsnaps.
In the picture you can see the arrow pointing to the screw hole that hides below the label in my mouse.
Step 3: Find the Culprit
In my mouse, the LED hides under a plastic cover, you need to remove the cover and the red LED to replace it for a 875nm infrared LED.
The adequate IR led you should get has a clear white plastic, there are some other IR leds with a dark plastic but those are of another wavelenght unsuitable for the mouse optical sensor.
To replace the LED first lift the cover and carefully unsnap it from the LED to get the led uncovered, then desolder the 2 pins of the diode from the PCB.
Step 4: Put the New LED and Reassemble
Making note of the correct polarity of the LED diode (both have a small dent on one side, this is the cathode, the negative lead), bend the pins on the new IR led the same way it is on the red led, put the black cap and solder it to the PCB.
Test if the mouse is working fine. If it is, reassemble and enjoy your silent IR mouse!.
If it doesn't work, make sure that the LED is actually lighted using a infrared camera and also, it has to be very bright, some older less powered LED's wouldn't work with the mouse.
The first picture shows the mouse working with the IR led, and yes, it's actually working, see?
no red light=Success!
The second picture shows the mouse shining in an infrared camera.
