K790a failure

Hi guys, im new in the forum so i dont know if this question has been done before but anyway here i go:

I have a K790a new phone, it works perfectly, but!!!!! when i stop using the phone it turns off, so if i wanna turn it on again i need to remove the battery and then it turns on again if i dont remove the battery i can't.

is this a software or a hardware issue?
im learning about firmwares right now cause a friend told me theres a way to upgrade the firmware and maybe it will help, can i have your opinion about this problem?

regards.:)

Use SEUS ( Sony Ericsson Update Service ) to update the firmware, free and you'll get the latest firmware :)

Sounds like hardware issue, having a latest firmware is good, so do the SEUS update, but I'm almost sure, it won't solve the problem.
When did you buy it? If it's SE retailer, they'll probably will fix it for free...

:mad: no, they dont want to validate my warranty , i have 2 weeks using the phone and the warranty its not valid now, fucking store, they say maybe i did something wrong with the phone, i have no option i must fix it by my own

when the phone goes to stand by it gets freezed... i did SEUS but still the same, according seus i have the latest update but its wrong, i was checking and its not the latest one, but update its always the same.. ill buy a log to flash it by my own :D

You should go to the shop that you bought the phone and give it to the technician.You have waranty