S1200V3RPM can't enter setup

Hi,

I'm setting up the S1200V3RPM with Xeon v3 E3.

When the machine boots, it shows the fancy Intel Server Board logos, but hitting <F2> to enter Setup doesn't work.

If I power the machine with the keyboard cable disconnected, it will boot and run the Ubuntu LiveCD without a problem.

Please advise how to enter setup.