Sony Ericsson :: W810i Phone Not Charging?

I have W810i and the problem is that it won't charge - i just want to make sure if the problem is in phone battery or faulty charger? The phone was turning itself off when slightly dropped on table and such. But other then that, it was working and today i brought it to the service and the repairman put other charger and it charged, but only after second attempt after he cleaned connectors a little. Now, i brought it home but it won't charge. The other problem is that it was charging only when i squeeze the connector into specific position, so i guess something with the connectors too, but i'm not sure which one, the charger or the phone. So, what do you think?