I have a Dragon showing the following symptoms:
1) The ATMEGA2560 on the board gets distinctly warm/hot to the touch. I normally run the Dragon inside its box, so I don't know if this is normal.
2) In AVR studio I can read and write the ISP frequency, and can read back the target voltage (correctly).
3) The LEDs on the Dragon seem to blink as I would expect, to indicate USB activity and connection to AVR Studio.
4) I have a whole bunch of mega48/88/128/328 chips, some of which may have debugWire switched on. I can't debug (using DebugWire) or read the signature (using ISP) on any of them.
5) When attempting a debugWire connection, there is no evidence of any activity on the RESET/debugWire pin (looking at it on a scope).
I conclude that some part of the Dragon is dead, but I would be keen to try to resuscitate it if anyone has had similar experience or has any ideas.
Thanks in advance.