Question on bad PSU or monitor?

Just started yesterday, when I come out of sleep mode the monitor doesn't come back up and I have to shut it down and restart pc then the monitor works. Is it a bad power supply or the monitor going bad. I have no other issues with the monitor. I did take the power supply out and cleaned it, it was full of lint and now after I post this I will put pc back in sleep mode and see if that was the problem. Other than the monitor not coming back on after sleep I have no other issues, I hate to buy one thing and it winds up to be another, so maybe someone can shed some light as to what it can be. Now both my monitor and power supply are pretty old but like I said I have not had any other problems but the sleep mode thing.

750 watt cosair pSU

3.20 gigahertz Intel Core i5-6500
256 kilobyte primary memory cache
1024 kilobyte secondary memory cache
6144 kilobyte tertiary memory cache
64-bit ready
Multi-core (4 total)
ASUS DRW-24B1ST a [Optical drive]
PLEXTOR DVDR PX-880SA [Optical drive]

SAMSUNG SP2504C [Hard drive] (250.06 GB)
WDC WD1000DHTZ-04N21V0 [Hard drive] (1000.20 GB)
WDC WD2500AAKS-00F0A0 [Hard drive] (250.06 GB)
AMD Radeon (TM) R7 370 Series [Display adapter]
LG W2253 [Monitor] (23.0"vis, February 2010)

Read your problem description and I'm not sure sure it is either PSU or monitor. You said this started yesterday. Have you checked Windows update history to see what has been downloaded and installed in the last few days?

2017-08 Security Update for Adobe Flash Player for Windows 10 Version 1703 for x64-based Systems (KB4034662)

2017-08 Cumulative Update for Windows 10 Version 1703 for x64-based Systems (KB4034674)

I read you said Sleep but is there a chance it was actually in a deeper sleep, hibernation. ​No, I read bad things about that so I made sure I don't even have it to select on the start menu.

To shutoff hibernation as a test, enter this command in a Command Prompt(admin)
Did this too
powercfg -h off

To turn it on swap out the word off in the command above. Disabling hibernation will disable Windows Fast Startup. You have SSD so it should be a minor event.
No SSD drive

You could also try going to your power plan and resetting it to default, restart and then customize.

I will try it and let you know.

Ken[/QUOTE]

Caledon Ken said:

Saw Samsung and 240GB but missed the words Hard Drive, my mistake.

well it seems to work but it takes longer than it used to, to open. I will find out better when I put it to sleep for the night. The keyboard and mouse light up almost instantly but the monitor is a bit slow to open. I also just updated my BIOS and nothing seems different by doing that.