I have been using a refurbished Samsung s24b300hl 23.6in monitor for about 2 years now.
I have had issues with it from roughly a year after buying it; the back light flickers horrifically on some of the preset options in the menu. Generally the one that worked the most was called "dynamic contrast". What's odd is sometimes it works fine for days and other times it is flickering on and off rapidly for extended periods of time. At it's worst the backlight stays off for ages until I use a torch to change the brightness settings in the menu (FYI it tends to work more and flickers less when on higher brightness's).
Currently it has taken a further step, where my desktop screen flashes up for a split second when I turn it on or replug the hdmi cable, yet goes blank (completely black, not just the backlight when I shine a torch on it).
I'm pretty sure it's monitor related (as opposed to cable/ graphics card related) as I've tried it with a VGA cable too which doesn't work (but used to work before this issue), I've also tried both hdmi and VGA in my laptop - which it is not being detected through at all, so it suggests to me the monitor is faulty.
I'm a mechanical engineer and I don't have a problem getting hands on, I just hoped someone with more expertise could give me a verdict as to what it's most likely related to before I go poking around inside?
From what you say, I would agree that this is a monitor problem. Normally, unless you are a person who can trace faults to individual components and replace them, then there are no servicable parts inside the monitor. You acn replace the whole board or the screen, but it is usually best to buy a new one. If you can try another monitor first just to confirm what we already know.
I hope you sort it but Im afraid thats the best advice I can give.