I have a problem with my monitor. While I am surfing the internet or playing games, my monitor is unsteadily bright. It goes normal and then dark again every few seconds. This is really annoying because it affects my gameplay. Please help.

Is this a new problem? Is this an old monitor? CRT? LCD? Has it been moved lately?

Do you have another monitor that you can try/ test?

Any large speakers or other magnetic devices in the vacinity?

Does the monitor have its' own settings' buttons? Perhaps a degauss feature?

Also check the Device Manager: Start/Run/ devmgmt.msc | Monitor

It was perfect until this morning when I turned on my computer and saw it. This monitor is CRT and it's kinda old (not sure how many years). I have two speakers beside my monitor, and they are not big. Not sure if that could be the problem. I have another computer to test it on but I can't try it yet. I looked in device manager and didn't find any problems. Anything else?