My Gionee phone suddenly turned off and won't turn back on?

[AC Question]

It's Gionee Elife E7 and it was working properly till evening but suddenly it's turned off, i don't know how bz when i saw the phone was switched off...but still it's internal memory disk drive is working when connected to the Laptop.....
some one has replied to pull out battery but battery is inbuilt.....so can't pull out from mobile without machine.