Originally Posted by mdc1983uk
Thanks for suggestion but i'm not so sure. I mean it charges fine turned off, it charges fine on 7.1.A.303. And another symptom is not being able to connect my PC to phone. Surely if it was just battery/power control it wouldn't charge from PC but would still connect and allow me to transfer files. I also don't have any of the random reboots the OP had. I'm so worried to send this in for repair. Last time they did a software update and sent it back with original problem. Then they fixed 2nd attempt but caused some cosmetic damage and it didn't last long. Then my operator replaced it as I said I lost trust in the repair centre. I only got this one Nov last year and already it's having problems... I'm either unluckyist T owner going or they have some serious issues.
Very unlucky... my T is one year old, I installed every kind of rom/upgrade/downgrade and still works flawlessly.
Could they have replaced your old phone with a regenerated unit?
Your USB port is ok, that's for sure.
Like any other electronic component, a fried power control could behave in many different ways.
Yours could have problem when it has to work with a firmware that manage the power in a certain way.
Even when you connect to your PC, the power control of the battery is called to manage the power coming from the computer: in fact the phone usually charges during any operation with the PC.
And this explains why the phone charges fine when turned off.
Now the question is: which is the power control ruined? The one of the battery or are there other power controls?
Let's make it clear: this is just my hypothesis
If you don't trust in reparing service, why don't you try to repair by yourself?
You need a screwdriver (for only one screw) and a guitar plectrum to open up the back cover.
That's all, it's very easy... on internet there are some video guides... but remember that this way you loose your warranty!