Mouse sensor seems to have broken

This usually points to sensor-level failure or firmware/power issues rather than something simple like a low battery. Test on Another Computer/Surface, Reset the Mouse, Re-pair the Wireless Dongle

• The sensor uses IR illumination, which is invisible to the naked eye.
• If you see no faint glow at all under a phone camera (IR can sometimes show up), it may indicate a dead sensor or no power delivery to the sensor.

• The G305 is fairly robust, but battery movement, humidity, or shock can loosen the tiny contacts connecting the sensor to the PCB.
• If the mouse has been stored somewhere it could have gotten warm, cold, or damp, the sensor might not be getting voltage.

Important: Opening the G305 will void warranty (though after 2–3 years, that’s probably not a concern).

Things to check internally:

1. Remove the shell carefully.
2. Look for burnt or discolored components around the sensor.
3. Check the sensor flex or PCB solder joints — sometimes a tiny crack can appear, cutting power.
4. If you’re lucky, it’s just a loose ribbon or solder joint, which can be reflowed with very light soldering.