Broken Arduino Mega magically repears after uploading bootloader.

Using Arduino IDE 1.x
4

Jantje:
I did a final try to upload the bootloader with avrdude and a AVR ISP which worked on the first try with this command

C:\Users\IBM_ADMIN>D:\arduino-1.0.2\hardware/tools/avr/bin/avrdude -CD:\arduino-1.0.2\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -patmega2560 -cstk500v2 -P\\.\COM11 -e -Ulock:w:0x3F:m -Uefuse:w:0xFD:m -Uhfuse:w:0xD8:m -Ulfuse:w:0xFF:m -F

That avrdude command does NOT upload any bootloader, it merely resets fuses. So, if that repaired it, your problem was not a corrupted bootloader, it was corrupted fuse values.