can an mcu be fried and still working with the latest program
No, but it might have lost it's bootloader in which case it may show this error too. Another possibility is that the USB coprocessor (ATmega16U2) lost it's firmware so the USB connection don't work anymore.
i also tried to burn a new bootloader but it didn't worked ... (i think the problem is that the master is an atmega using its 8MHZ internal clock that i've burned the bootloader myself )
Have you tried to use an original Arduino UNO with the ISP sketch as the programmer? You may also use another programmer but I don't think it's a clever idea to use an ATmega at 8MHz for a sketch written for a 16MHz UNO.