Introduction: Logitech MX 900 Batt' On/off Switch

Where to put an on/off switch for the batteries of the Logi' MX900 optical mouse? 

My battered mouse.

Step 1: Ingredients/tools

If your like me & you have piles of junk never thrown out this may be eaisier?
(I'll make it clear later on!)

1.small Philips screwdriver
2.solder iron/solder
3.thin electronic wire
4.Hot glue
5.small thin electronic switch

Step 2: Take Off Cover

Flip it over & take out the batt's that drain when left in/on.
The 2 screws that hold the top onto the base are located in the batt compartment & at the top of the sticker near the front roughly in between the 2 front skid pads.

Step 3: Where's It Going to Go?

Looking from above the mouse the 2 terminals for the batt's are near to the back.
These are where the switch is to be placed in between to create the on/off function found on the hyper expensive lazer mice that I am not shelling out for BTW!

Remove the 3 screws shown to lift the top board!

Step 4: Da! Switch

Got this switch out of an old bit of electronics left as junk.
Nice & small/thin.

Step 5: Start the Hack.

The  - terminal was de-soldered & the spring connecting contact slides out.  

Now I got another springy contact from some other junk of an old TV remote so as to save destroying the original 

Step 6: Make Hole for Switch.

Put the springy - terminal back into the compartment with the end facing toward the hole that is made in the base for the switch. Hold on!
THE HOLE FOR THE SWITCH.(I was getting to that!)
The switch will sit nicely flat halfway up against the batt' compartment with the lever slighly poking out from underneath the mouse.
To make the hole required for the switch I had to melt through the sole of the mouse with my solder iron as I have no crafty expensive tools but it may be done using them if your lucky enough to own them.
The unsitelyness can be smartend up with an exacto knife after wards  but only needs enough of a hole for the switch to operate in both directions.

Step 7: In Place.

Solder 2 pieces of wire form the terminals of the switch (after testing to make sure they are the make & not make terminals) then solder one of them to the springy terminal in the batt' compartment & solder the other wire to the - contact on the PCB of the mouse;from underneath as the same place the original springy contact came was terminated into the board.  

Glue the switch in place after testing the hole is  sufficient for the on/off action & replace the top circuit board ready for re-assembly. 

Step 8: Re-fitted

It fitted nicely without any bulge to complain about & the slight unsightliness is unseen any way really but can be given a bit of a spruce with an exacto knife to get rid of the excess melted plastic.