If you find that the power switch on your Produino controller is intermittent, or not working entirely, it may be possible to resolve the problem yourself very easily.
First, remove the battery. This saves unnecessarily powering up the controller during the process.
Now flick the switch between the on and off positions 20 times in succession.
Refit the battery and test.
How can this fix the problem? Often the contacts of the switch can become stuck meaning that they make an improper contact. Rapidly flicking the switch from side to side can free them up and restore it's function.