3GS syncs, wont charge

[kingdLo]

Got a 3gs running 4.1 unlocked on 6.15 baseband. The phone used to charge perfectly fine either computer or wall. Now it wont charge with the computer or the wall, its either hit or miss and it'll charge for 10 minutes at a time. I have a cheapo powermat type thing and same thing when it wants to charge it will. It syncs perfectly fine to the computer. I've tried running official 4.1 and just jailbroken. I'm stuck.

 

[Applejuiced]

Clean the port on the bottom.