Why does my video monitor shut off and go into standby mode when I play OFP?

This might have to do with an incorrect setting of your monitor's refresh rate. Check your Windows monitor refresh rate setting and confirm that it's appropriate for your monitor's make and model.

If the monitor refresh rate is correct, run the OFP preferences program and try setting your resolution to a lower setting.

OFP player ScreamingWithNoSound has helped out another player with the following detailed suggestions:

First, check the specifications of your monitor. If you have a 17" monitor, your maximum resolution will be 1600x1200 (quality monitor) or 1280x1024 (cheap monitor). If you set the Windows display resolution of your monitor above the maximum resolution of your monitor, you will get a "Signal out of Range" or a "Signal Not Valid" message or a blank screen with your monitor's power on indicator flashing on and off.

As well as checking your monitor's maximum resolution, you'll need to check the maximum refresh rate for your monitor at the resolution you plan to use. For example. I have a 17" monitor which is capable of 1600x1200 at a refresh rate of 60hz and 1024*768 at 100hz.

I find that a resolution of 1024x768x32 at a refresh rate of 85hz is the most comfortable for me. At 75hz, the screen flickers for me too much. 

There are several ways of adjusting these settings. The simplest, is to open Windows Control Panel> From there open Display. From there, click on the SETTINGS tab and then on ADVANCED button. From the current display select ADAPTOR or MONITOR, depending on your Windows version.

You should now have a drop down box that allows you to change your monitor's refresh rate. If you have a Plug And Play monitor, it should automatically hide settings that won't work. If in doubt, always click on the APPLY button after changing settings, as this make it easier to undo your setting changes should that be necessary.

If all of the above doesn't resolve your problem, the next step is to run DirectX's DXDiag utility program. DXDiag can be run by clicking the Windows START button, select PROGRAMS, select ACCESSORIES, select SYSTEM TOOLS and then select SYSTEM INFORMATION. From the SYSTEM INFORMATION window, click on the TOOLS menu bar item and select DirectX Diagnostic Tool. This will run DXDiag.

When in DXDiag, click on the MORE HELP tab. Here, you will see a button called OVERRIDE. There you can set an overriding refresh rate. Set the override value to a refresh rate that you know works for you. If in doubt, set it to 60hz.