Don't know where to post this but seems like a MB problem so here I go. Lately my PC's monitor been turning black randomly. (It is absolutely random, first time was when I was turning off the monitor which had me thinking it was the monitor but... the second time was when I plugged my mp3 in the USB slot...). It happened twice and when it goes back, there is way I can get it turn back on. It has nothing to do with the monitor because I have a few spare and I interchanged it with wire and all. The first time it happened, I left it alone, turned off the power and hold the power button for like 30-60 second. After a month or so it worked again(I did not check it in between). The second time, which just recently occurred had me worried because it happened again. It turned on with a long bio screen load, but it worked. The problem is just weird and it is similar to another PC of mine which I fix by replacing the motherboard...
Are you running off the motherboards graphics (IGP) or from a separate graphics card?
An easy way to check if its monitor, monitor cable, graphics card related is to press the power button once while windows is loaded. If your computer is operating properly (just no display) then it will shutdown slowly, pressing the power button while its loaded into windows is just like clicking shutdown. Though if it doesn't then theres something further wrong with your PC and you can rule out monitor/cable problems.
Did you change the monitor cable? If you are running IGP then get a graphics card and test with that. If your running a graphics card test with the IGP or another graphics card.
Thats a few things to look at.
It happened again, this time I remember to press the power switch "just like clicking shutdown."(The no signal screen happened when it was started up) It was really weird, it continue to start up really slowly for some reason but it did start up. Though it was quite laggy. Anymore insight?
Sounds like a display problem. Are you running from the IGP or a seperate graphics card. If your running IGP you should find a graphics card to use and if you running a graphics card either run a different one or run off the IGP.