Factory firmware restore on gen6d

Hi all,

I have a gen6d electronic board for my prusa. I wanted to change the factory firmware to repetier. Therefore I backed it up with winavr ( cmd rule: "avrdude -c avrisp -b 38400 -i 10 -p m644p -P com4 -F -U flash:r:factory_gen6d.hex:i" )
Now I wanted to get back to the factory firmware by writing my saved hex file. I tried this with winavr, cmd line: "avrdude -c avrisp -b 38400 -i 10 -p m644p -P com4 -F -U flash:w:factory_gen6d.hex:i"
But I keep getting errors with the writing. He doesn't even start it. In attachment a picture of the error. It says programmer is out of sync.

Does anyone knows how to fix this? I'm kind of new to all this.


Thanks in advance!