Sometime you will have a computer having a problem with USB ports  not powering some USB input devices. one cause could be that a capacitor on the motherboard has gone bad. 

That capacitor can be identify by looking for a burnt capacitor located to the the right of the possessor socket or you can test the capacitor if it is bad.

This capacitor control the voltage flow to the USB ports, if you find it to be bad just remove  and replace with the same type capacitor. hope this fix  will help in your computer repairs 

Please see image below for an example of the capacitor and location.