Computer turns on but monitor is blank or says “No Signal”
This problem can be caused by a few things but typically it is caused by a failed power supply unit in your computer. “Wait a minute!” I hear you say, didn’t i just tell you that my computer turns on! Well, the thing is, hardware failures are not always black or white. Sometimes you can get varying degrees of damage. Just because you can hear the fans running in your case doesn’t mean that the power supply is doing what it should do. Before declaring your PSU (powersupply unit) a write off however, it is usually a good idea to test a few basic things.
First, you should check that your monitor (VGA) cable hasn’t come loose. Second check that your monitor is turned on 
Derrrhh!
Ok. Now that those two are out of the way, its time to start swapping hardware. At the moment it is still a little ambiguous whether the power supply is the culprit but more than likely it is, so before going out and swapping more time consuming hardware likw your motherboard or graphics card which requrire you not only to install the new part but also the associated drivers, I would recommend that you try borrowing a power supply from a friend, or if you have another computer, you could use that for a quick test.
If you are still having problems after trying a new powersupply, shoot me an email via the contact form on this website and I will do my best to help. Good luck!
Incoming search terms:
- my computer turns on but the monitor says no signal
- computer monitor says no signal
- computer turns on but monitor is blank
- computer turns on but monitor says no signal
- computer turns on but no signal to monitor
- monitor says no signal but computer is on
- when i turn on my computer my monitor says no signal
- my computer turns on but monitor says no signal
- computer says no signal
- computer turns on but no signal
Tagged with: blank monitor • no signal • power supply • power supply unit • powersupply • psu
Filed under: Hardware • Troubleshooting
Like this post? Subscribe to my RSS feed and get loads more!
Hi i have tried this but it stilld does not work. I changed the battery and the ram cards and the grahpics card but it still does not seem to wanna work. Any suggestions??
Hi Braeden, did you also try a different power supply?
Hi, i have a gts 250 and i ran the thing on a secondary psu with 5amps on the +12v rail and the cards minimum is 24amps ;O Yikes! well after that the pc would turn on fine and stuff every fan every motherboard light and sound was correct, even gpu fan was working, but no display on monitor.. in fear i switched everything back to the main power supply 450 watt with 25 amps on the 12 v rail and my other psu is only powering my case fan/rail lights/ and power switch light now… but i still have the same no signal issue… i called evga support and they stated its my 450 watt powersupply and said that a weak psu couldnt do any harm to the gpu only not let it work/turn on.. but i was able to run the gpu before on the main psu, i only split it so i could add some extra stuff
bad move lol. Well, its not giving me a signal.. so whats the issue, psu or gpu 
thanks
Desorath, I would have to agree with evga support, I can’t see a weak psu damaging a graphics card, it just wouldn’t power the gpu.
I know this will sound really stupid to you, but how do I check if the power supply works? I’m not even sure what that is exactly.. =/
I have switched out monitors and the new monitor says the same thing, No Signal.
Thanks!
dudes
my system suddenly shutdowns itself and restarts its self
some times it restarts properly
but some times, though the CPU restarts but the monitor shows no signal…..
after some time keeping it alone undisturbed, later it starts again normally with out problem
can anyone tell me whats the problem
Hey, just tried my friends power supply and still no luck. He has exactly the same voltage plug as me so it obviously made the desktop work but not the monitors. I have two monitors and neither of them picked up any signal. Tried turning my computer off from the back, etc. Still no luck. Would really appreciate any advice please!
This sounds like it could be an overheating problem. Your PC hardware will shut itself down when it gets too hot to prevent permanent damage.
Check the fans and make sure they’re all working
I changed the power supply but my computer still not working. The fan is not turning, no sound. When I open it, I just see a small green light. My three years computer did the same. I then bought the new computer, it worked only for about 30 minutes, and now I am experiencing this problem.