Redmi 1S - Navigation Keys failed

[patkim]

I have Redmi 1s that's now 3 years old. Ironically it's navigation keys stop working randomly.
When they work they work when don't they simply do not respond. I have to reboot the phone a number of times and then sometimes they work. It's hard to tell if this is hardware or software issue. I have latest MIUI 8.1 so can't upgrade any further.

I am going to do a factory reset, does anyone know if navigation keys are required during the process of factory reset? If yes and they fail at that point my phone could be rendered useless, hence this question.
Thx.

 

[SaiyanGoku]

Do key test in recovery mode. Or there should be an app available for checking that.

 

[patkim]

Yes in recovery mode it's only the Volume UP/Down and Power keys in use. So looks like Nav keys won't be used. Anyhow for now I have enabled Quick Ball feature from settings and sort of converted the phone to a sort of full touch phone!