Hi got a C902 and it keeps turning itself off, how can I stop this, do I need to update the firmware / software or something. I'm a bit of a muppet when it comes to mobile phones.

did it come with a lead that had a mains plug on one end and a smaller plug on the other end?

ho ho ho 🙁

Probably the firmware – I've heard of a few of these doing it. Try the sony ericsson site, or the network you got the phone from.

SE Site:
http://www.sonyericsson.com/cws/support/softwaredownloads/detailed/updateservice

yup – mine does that. Apparently it's a design fault on that phone. Mine's so sporadic though I can't be bothered going through the faff of sorting it out – it's a welcome surprise to find my phone's been off without me knowing!

firmware will fix it (so some level) but mine is doing it less but still does it with the latest firmware..

can't be arsed with it now..

Are you using an old SIM?

I had a similar problem with a new Nokia 5800 and an original SIM card which was about 10 years old. Apparently there was an incompatibility betweeen the phone's OS/Firmware and the SIM. Took it to my provider, Vodafone, and they created a new SIM with my number and I've had no problems since.

Had the same problem with my C702, firmware update sorted it out.

http://www.singletrackworld.com/forum/topic/o2-not-being-very-helpful-any-thoughts

Nothing new here then?

Apparently it was a known fault with early software versions. Make sure you have the latest version (easy to check if you go to the SE site as suggested above).

Oh, and if you want to extend battery life, make sure 3G is turned off.