Here is some troubleshooting information for that alarm:
The 971 Alarm (DRIVERS FAILED TO LOAD) is a time out alarm at power up generated by the Main software when it did not detect the presence of the Enet card in about 30seconds after the main software fully loaded.
Can be cause if the mill code (FV) version is corrupted
Can also be generated if you cycle the power on the machine to Fast.
Turn off machine and wait 5 seconds before powering back on.
Verify Supply Voltage to E-net card should be at least 4.75vdc, with the card
Verify that Data & address buss to the PC104 are well seated.
Check ribbon cable connection from HD to PC104 PCB, reseat if possible
Remove all connections to the E-net card, USB cable, Rs-232, & E-net cable: cycle power
Contact your local HFO if everything else fails.