Hi guys, I have a 3g which is showing as 20% battery remaining. If I plug it in to the mains power the phone shows the black screen with the icon for charging. The phone then boots itself up.

With the phone booted up the battery icon remains red even though its plugged in and does not show the charging icon.

When I plug the phone in to the PC nothing happens at all.

I have another 3g which works perfectly well on the main charger and on the PC (so we can rule them out).

I have replaced the dock connector with a brand new one, no change. I swapped the battery from another 3g and it still is doing the same thing!

Is it the mobo board? Any known solutions?