I have a naga v2 pro that feels like the switch on the underside of the mouse has gotten loose or something. If I change it to Bluetooth, it doesn't change to Bluetooth unless I apply constant pressure and will revert back if I stop. Similarly, changing down to 2.4ghz sometimes doesn't work given that the lights are all off. 

If plugged in via cable everything is fine, but that defeats the purpose of the wireless aspect. 

No warranty, so I'm open to mouse surgery if there's a tear down guide anywhere.