Can not upload to MEGA 2560 anymore

Hello all, I'm hoping you can help me with a problem we're having.

One of our many MEGA 2560s is no longer accepting uploads. The currently-uploaded sketch works fine, however (that is, we've been able to upload to it in the past). This has been tried on three different PCs (all running Win XP) using Arduino 1.0 or greater; these PCs have no problem uploading to any other MEGA 2560 we have in-house. I see no evidence of physical damage either.

The upload process never completes; LED13 flashes once, then a quick blink from the TX/RX LEDs, and then nothing. If I enable verbose mode on upload, I see:

    avrdude: Version 5.11, compiled on Sep  2 2011 at 19:38:36
             Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
             Copyright (c) 2007-2009 Joerg Wunsch
    
             System wide configuration file is "C:\Documents and Settings\astavrow\Desktop\arduino-1.0.1\hardware/tools/avr/etc/avrdude.conf"
    
             Using Port                    : \\.\COM10
             Using Programmer              : stk500v2
             Overriding Baud Rate          : 115200
    avrdude: Send: . [1b] . [01] . [00] . [01] . [0e] . [01] . [14] 
    avrdude: Recv: 
    avrdude: stk500v2_ReceiveMessage(): timeout
    avrdude: Send: . [1b] . [01] . [00] . [01] . [0e] . [01] . [14] 
    avrdude: Recv: 
    avrdude: stk500v2_ReceiveMessage(): timeout
    avrdude: Send: . [1b] . [01] . [00] . [01] . [0e] . [01] . [14] 
    avrdude: Recv: 
    avrdude: stk500v2_ReceiveMessage(): timeout
    avrdude: Send: . [1b] . [01] . [00] . [01] . [0e] . [01] . [14] 
    avrdude: Recv: 
    avrdude: stk500v2_ReceiveMessage(): timeout
    avrdude: Send: . [1b] . [01] . [00] . [01] . [0e] . [01] . [14] avrdude: Recv: 
    avrdude: Recv: 
	avrdude: stk500v2_ReceiveMessage(): timeout
    avrdude: Send: . [1b] . [01] . [00] . [01] . [0e] . [01] . [14] 
    avrdude: Recv: 
    avrdude: stk500v2_ReceiveMessage(): timeout
    avrdude: Send: . [1b] . [01] . [00] . [01] . [0e] . [01] . [14] 
    avrdude: stk500v2_getsync(): timeout communicating with programmer

This repeats ad nauseum for as long as I leave it running. For the record, in troubleshooting this issue I'm trying to upload the 'Blink' example sketch, that is, well-known and well-tested code.

I tried running the loopback test but nothing was echoed back. Similarly, I can't open a connection to the serial port, or rather, I get no reply from the MEGA 2560 in question when I do.

Pressing the reset button gets LED13 to blink twice, so I believe this means the bootloader is okay; please correct me if I'm wrong about this.

There is no apparent damage, although one person on our team suspects they saw an ESD event when connecting the cable from the MEGA 2560 in question to the PC (at the PC port, which appears to have come through unscathed). I can't corroborate this.

Oh yes, and lest I forget, I have "Arduino MEGA 2560 or Mega ADK" selected as the board, and the correct COM port is selected to.

Any thoughts on how I can further test this before declaring the board KIA?

Thanks in advance.

If its a "fake" (ebay, sparkfun, etc.) throw it in junk...
If its an original, try to spam on forums for help (i remember my post had like 100 000 views, but no solutions that worked)...
If you don't get help you can always salvage connectors from the board and then throw it in trash...
Best regards, xXvjeko
P.S. there are cheaper faster mega alternatives like Microchip's 32'bit pickit for 49$ (original) with more outputs and more powa ]

It's an original Arduino unit.

We're probably just going to trash and replace it as it's more cost-effective than trying to troubleshoot the board.

If you have the ability to reflash the bootloader on the 2560 chip and USB to serial code on the 8u2, I'd give that a shot.

Keep in mind that damaging ESD effects are not visible or cause enough shock for most people to feel it. So it could have been damaged and you not know it.

bypass the usb and use a programer to load a fresh bootloader