Monitor goes dark periodically for a few seconds

This is one I can't figure out, in spite of searching Google for answers to others with a similar problem.

I have a ASRock Extreme 4 Gen 3 with an i7-3770k CPU and running Windows 7, of course. Can't see why I'd want to upgrade to Windows 10 and cause incompatibilities with all my software which runs wonderfully for the most part.

I'm using a dual monitor (Dell 25" U2711 and 24" widescreen P2412 as a secondary) and get occasional blackouts on the primary monitory ONLY - not the secondary. We aren't talking every few minutes, probably once every few hours, sometimes more frequent, other times it doesn't appear at all. Certainly usable but can be very annoying.

The primary is connected to the Display Adapter with the secondary to the HDMI. I have tried to update the motherboard and the display drivers but this behavior continues to persist. Wondering if there is something I've missed - I think I have the latest drivers for this mobo, which now is almost 5 years old but one of the most rock solid I have ever owned.

Hello klinky, First to do is to determine whether it is the monitor or the computer. Swap the video cables on the monitors. Then when it happens again, is it the same monitor, now the secondary, or is it the "good" monitor? Monitors can do this, I have experienced this myself.

I have had the same problems with my Samsung SyncMaster 204B's. They suffer from using some cheap capacitors. I have been using dual monitors for years. I am now running three. It's really nice. You will enjoy the duals.

Stan

Yes you need to test the affected monitor and it's cable on another computer. One with a known good display. I suspect that the monitor is bad and they don't last forever.