Monitor black off while CPU power runnning [Solved/Closed]

 Martin -

I am having a problem on the desktop PC. My monitor screen is black off while the CPU is still running.

I had run the monitor on another CPU where it worked fine. I had try to uninstall the graphic card Sapphire X550, shut down & switch off the PC and then remove the graphic card from the expansion plot.

After re-plugging the graphic card and switching on the PC, I installed the graphic card driver again. Now, the desktop is working as normal.

I had try to set the MHz to the lowest MHz at the right click desktop properties. After a few day, the same problem come again.

How to find which part of the system is creating issue - graphic card or the motherboard?

Thanks in advance for the help!

System Configuration: Windows XP Internet Explorer 6.0

9 replies


It's the motherboard problem that is creating issue. I had faced the same problem a few months ago. That time, 8 small ICS had burned out. Would suggest you to first try this:

1. Disconnect everything
2. Unplug power
3. Push 2-3 times the start button to eliminate remaining current
4. Reconnect everything
5. Push the start button

If it does not work, try this:
  • Try pressing the NUM lock key when your PC is on and monitor has blacked out.
  • If the NUM pad key light (green) lights up (there are 3 small lights on the key boards - it's the 1st one I'm talking about) then your Motherboard is ok.
  • If not green light does light up, you need to consult the computer mechanic.
Thank you

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mine video card
It's Monitor, %100 sure
I have this problem with my PC. Everything is working except the monitor screen is black even thought the monitor is on. I swapped graphics cards thinkin gthat was the problem. 2 weeks later it started again. I have all brand new components (2011 socket mobo, intel i7 3820, 32 gigs 1333-1600 ram, MSI radeon hd7850 twin forzr 3, sata DVD rom, SSD hard drive) except 2, my monitor and my power supply. I had the same problem with my old graphics card (radeon hd6570) as well as the new one. It's power supply problem. running and old modular 550 power supply that's 5-7 years old.
Thank you for this! It was comforting to verify that it wasn't the motherboard! I found I had to remove the additional memory I added a year ago since I just now did a system recovery (computer needed to be in original config.) Oddly, I did not remember that of the 4 memory slots, the original (primary) RAM, starting from the left, sits in the 1st and 3rd. The additional RAM is placed in slots 2 and 4. When I removed the 2nd and 4th, it solved this issue for me.

I had the same problem and it took me several weeks to find out what was wrong with my PC.

For me it was the cable which connects the monitor to the PC. The PC doesn't give a signal to the monitor. It could be that a connector pin is bent.

I had the same problem and found a solution - or found out what was actually the problem.

First of all let me say that it is not the CPU or the harddrive!

I tried un-pluggng all the cables and re-plugging it all back in again - but nothing worked.

Then I pressed the on-button on the monitor and held down the Auto button which is also located at the bottom of the monitor screen.
I had a menu option that said 'repair windows environment' 'advanced option' 're-start windows' etc.
I chose to 're-start windows' - this restarted the computer but I still ended up with a black screen.

So I repeated the above process of pressing Auto and on-button, menu came up. I selected option 'repair windows environment'
Then after loading and 2 screens that flashed - I got a black screen with white writing, a little down the screen it said something like 'repair windows environment' and then a count down timer in seconds. This option is a waste of time as there is nothing wrong with Windows. I selected the next option down 'start as normal' and pressed enter.

My screen was back!!

I closed it down and re-started it to see if it worked. Black screen again!

So then I started to adjust the cable head - the part that is plugged into the monitor.
First time it did not work but I did see some light flashing so I continued adjusting then pressing the on button on the monitor and suddenly it came on, I could see my desktop icons.

I am having this problem a lot now and have to always adjust the cable head - so I think it must be the cable.

Good luck!
It is not necessarily the cable it could be thew video card where it connects to the cable, in any case I believ it is bad and needs another video card if you have already tried another cable...borrow one from your printer or other device and try it.
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Wednesday October 8, 2008
Last seen
June 15, 2019
Yes it is the Video card or the motherboard. How do you tell which one? Only by replacing one or the other.
This happened to me. I opened up the computer and took a look at the video card (zotac geforce 7300), it is slightly over a year old. It looks like new except the capacitors are all blasted out the tops. Like this article talks about

Too bad it is just out of warranty. Pretty lame.
I had same problem , the monitor blacks off with CPU running
I solved the problem by removing the monitor cable from the backup battery and connecting it to electric outlet
Right click on desktop->Go to Personalize -> Screen Saver -> Change Power Settings -> Change Plan settings -> Increase the time for Turn Off Display

All the best :)
I think this is a thermal issue with this monitor. I am now on the second monitor from dell and both have had the issue where it starts shutting off after 30 or so seconds. The power button remains green but the screen is black. I have rigged a 60mm fan, approx 4CFM, to the rear louvers of the monitor to blow inward. This keeps my monitor going. If I turn the fan off it shuts off in about a min. From what I have noticed there is probably some issue with the thermal cutout switch or the thermal management design all together.
hello dell monitor have some capacitor problem in power supply board inside monitor I have replace 25 monitor capacitors and all of them are working fine
Yes, yes. I have a problem with my computer. And it is a thermal issue. Every day you can get on an hour and then it blacks out. People say to get canned air and clear the monitor and things of dust.
If so mething is overheating you need to find out what is! Overheating however usually indicates a problem with the power supply.
Just keep turning the monitor off and on until it stays on. Eventually it will. It took me about a half hour of turning it off and on before it finally stayed on. Then don't ever turn it off again, it might not come on again. I got the tip from an online forum - it works!
I disagree about the overheat if you only just turned the pc on, it cant overheat that fast. It is the video card where it connects to the cable or video/graphics port thats why she had to tweedle it.
Turning the monitor off and on does work - the first time. But if you have a power outage that turns your computer off - you are in the same boat except that it won't come back on no matter how long you turn the monitor off and on.

I did get it stay on after changing the sleep mode to NEVER. At least until we had a power outage.