Dead chip after programming bootloader

I have been working on bootloader code on the mega. I programmed the bootloader via usbtiny ISP programmer over 15 times today. A couple of times it failed but I would just do it again and it would be OK. The last time I did programmed it failed and now I cannot talk to the chip at all. I am using usbtiny and avrdude. I tried a different usbtiny programmer and tried the programmer with another board to make sure the programmer was OK and it was. I rebooted the computer and still nothing. Any idea of how to recover the chip, its a mega 1280.

Thanks

Over the past day or 2 I have reprogrammed a 2560 about 200 times. (with the bootloader code I just sent you) It didn't fail on any of the programming passes. I have been using the buspirate with the STK500v2 firmware installed.

I can't think of much to try except maybe try with a slower baud rate and double check all the components.

Also if you have an atmega328... you can try recovering it with the HV rescue programmer.

You'll have to modify the code slightly, but it should be obvious where. Worked great for me on a 2560 when I needed to recover the fuse bits.

Jeff

Thanks, this link is great. It answers a lot of the mysteries of high voltage programming

Mark