My 902sh cannot power on sometimes

My 902sh cannot power on sometimes!

I press the power on button , my 902sh
cannot power on, then I open the battery cover,
take the battery out, and then .put battery inside again,
close the battery cover .
After that I press the power on button again,
my 902sh can power on again!

My 902sh is using the sx813 firmware 1.03
before this problem is not happen and this month
it's happened for 3 times.

I have press the master reset b4, may I know what kind
of problem arise in the phone,is it better to change the
sx813 firmware from 1.03 to 1.02?? any good suggestion
to solve this problem????

Thank you !