Hi all,

i have a bit of a problem on my iphone 3g running 4.1 firmware ( yeah jailbroken =) anyway the thing is, when i lock it and then it normally goes in sleep mode, after i leave it like that for a bit ( 1-2 mins ) it would automatically turn off so i cant receive calls anymore and i have to boot it up again...its really frustrating.

Brightness regulation does not work.
and After pressing a couples time the power botton screen becomes white.

I had this problem back on 3.1.3, so i decided to update to 4.1 but it does the same thing....

Thank you for your support! =)

Did you ever replace the battery in this phone? This can happen if you replace the battery with a non-OEM / non-Apple battery. It can also happen if you have any old Cydia tweaks that relate to power management (insomnia, etc.). Have you done either?

no,never changed the battery, and the firmware im using is not even jailbroken right now.

I did change my screen some time ago though.

A lot of 3G/3GS users experience this problem right before their batteries go completely dead and need to be replaced. Quickly google searching points to many similar problems and one resounding solution of replacing the battery. Looks like that may be your best bet. You can get aftermarket batteries for as cheap as $5, though I do recommend OEM only if you want to be sure everything works.