Stephane, you may want to perform something else before replacing the motherboard,
- Please download BIOS version 0038 (.bio file) save it on an empty flash drive.
- Remove all hard drives, optical drives and leave only 1 memory stick.
- Remove the BIOS jumper while the system is off.
- Plug the flash drive and turn on the system. You may be able to see the screen while the BIOS is being update, if not, please wait for a few minutes.
Please let me know.