I have a sony ericsson c902 and the phone was dead , so i put it on charge and it came on then about 10 seconds later it turnt off

The C902 is a camera phone by Sony Ericsson.
If you purchased your C902 with a cellular plan, it would be locked to your company's network and can only be used with that network.
If you want to switch networks and continue to use your C902, you have to get it unlocked from the current network.
The simplest way to unlock your C902 is through remote IMEI unlocking.

1.Obtain the unlocking code for Sony Ericsson C902 from your network's support desk.
You can call them up and talk to a customer support representative.
Request the unlock code and give them the phone's IMEI number.
As an alternative, you can purchase the unlock code from the websites such as Unlocking,
FonesZone or UnlockItNow.
You will need to provide the IMEI number on the websites.

2.
Close all applications to reach the standby screen of the phone.
3.
Press the left direction key on the navigation pad.
4.
Press the * (asterisks) key twice.
5.
Press the left directional key once again. You will see a menu titled "Personalize."
6.
Select "Network" in the menu. Select "MNC2" in the second menu that appears.
7.
Enter the unlock code you obtained in Step 1 and select "OK." This will unlock the phone.
http://www.mobileunlockguide.com/sony-ericsson-c902

What is the problem with your Sony Ericsson C902.?
If you are seeking for an unlock code you can get it from http://www.onlinegsmunlock.com/sony-ericsson-c902/rs7wp9/ at affordable and low cost.

Please elaborate on your 'charging tips' issue with the sony ericsson C902.
the more info your provide, the more helpful we can be.

format memorycard switch off and on phone ,go to settings reset mobile,install new software in mobile

check u phone is all lock or not,is sp lock or network lock,just unlock only.

if only 8 weeks old take back under warrenty not even worth sorting although i suspect faulty software in the phone

almost 100% chance that you have a faulty battery. try swapping it with a new one.

I forgot the security code sony ericsson cyber shot

Take it to the dealer you received it from, ask to try a different charger i think the problems there.

Hope I`ve helped

there is a chip (cam) and a software that they can comminicate. it looks like they cant. need to get service.