Hi everyone! 
I have a big problem with my board (an Arduino ADK, wich is equal to Mega2560 except for a host USB port). I've been using it for about 2 years now and it has always worked smoothly. However, yesterday it started having this issue:
I plug the board into my PC, it recognises the device as Mega ADK and automatically installs drivers. Then I load my code from the IDE (after having selected the proper board and COM) and it does this: the bar quickly fills to half, then closer to full but here stops and buffers for
1 - 2 mins before showing me this error message
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_ReceiveMessage(): timeout
avrdude: stk500v2_getsync(): timeout communicating with programmer
In addition, RX TX LEDs never blink.
I want to specify that I tried on other computers (I'm using Win7 64b, tried also on WinXP), tried to upload different codes, tried to uninstall COM and change it, tried to manually install the driver (and tried old drivers), tried to open IDE with admin permissions.....but none of these have worked so far.
On balance, the board is recognised by IDE and PC but theres something in the communication. Hope the Serial communication chip isn't screwed...
Really need help on this one cause I just can't figure out how to solve it.
Thanks!