Tearing down a Microsoft Wireless Mobile Mouse 1000

Overview

I had this trusty ol blue mouse for a good four years before the mouse wheel started skipping steps due to the Alps relative encoder failing. Before this failure the mouse worked great on any surfaces that were not too reflective. Because of these two faults it's time to tear it down!

The Housing

The mouse housing consists of four parts. The top plastic shell makes for the left/right clicking surfaces. Below the top shell we have another housing holding the mouse wheel in place and preventing ingress of dust etc. into the PCB cavity. There is a battery cover plastic piece too.  

The bottom chassis housing holds all of the delicious insides of the mouse.

The Insides

The main components inside the mouse consist of the PCB, a reflective prism, and a mouse wheel mechanism. The LED seen at the top reflects light through the prism onto the mouse surface and then is recieved with a PAW3204DB-TJ3L ultra low power mouse sensor which does its own DSPing. The mouse wheel is attached an alps relative hollow shaft encoder EC10E1220501 and a push button. Two push buttons are either side of the scroll wheel for the left/righ button clicking action.

The PCB

In the central part of the PCB we find what looks like a small switch mode power supply powering the whole circuit. Below it we have an external oscillator for the Nordic nRF24LE1  microprocessor with BT capabilities. The micro is surrounded by decoupling caps and there are multiple pull up resistors beside each of the switches. There is also an on/off switch on the bottom of the PCB.

All in all a very simple circuit for a simple function. I wonder if rev C and below made it to production!