Mega 2560 connected to Vista.Basic Blink sketch uploaded with 250 millisecond watchdog code added.Pin 13 LED now flashes rapidly.Sketches will not upload.Releasing reset while trying to upload doesn't work. LED flashes fast as soon as reset button is released.AVRdude responds with timeouts.It will go into DFU mode and USB driver installs but Flip or AVRDude cannot open/find USB device.Disable "AUTO RESET" did nothing.What do I need to do to get this Mega working again?
I've had this problem a number of times. With some luck it is possible to recover by holding the reset switch until the upload starts and then releasing it. This will take several tries to get right. However, the most reliable way is to replace the bootloader. I fought this problem for a solid year before I talked someone into fixing it and providing a bootloader that works.Take a look at my blog page on the final resolution to this problem at: http://www.desert-home.com/2012/05/arduino-mega2560-wrapping-up-bootloader.htmlFunny, the folks at Arduino said they would make this part of the distribution quite some time ago.
No I don't. I have noticed that there a few people that have hit the same problem on the 1280, but no solutions have shown up.