Fixed frequency monitors only sync up to a single or very narrow range of horizontal and vertical sync signals. Unlike current multiscan monitors that sync up top a wide range of frequencies. The problem typically is getting the monitor / system to boot in low-resolution modes. Fixed frequency monitors usually only sync to the highest frequency possible, thus when you boot in low resolution modes the monitor will stay blank.
One way to get around this problem is to boot the machine using a multiscan monitor. Set the resolution and refresh rates to those supported by the fixed frequency monitor. Plug in the fixed frequency monitor. It will stay blank until the high-resolution drivers kick in. At that point it will display. The other problem is that if anything should go wrong with your system, you will need that multiscan monitor to trouble shoot the problem.