Why is my PC only showing a black screen?

My pc was fine when I turned it off yesterday morning, yet why is my screen showing nothing now?

• Upon pressing my HP's on switch, lights come on and fan as well, then a Shrill-pitch noise happens for 3/4 of a second followed by 2 identical-sounding ones which are each half that. {Beeeeep! beep, beep.} Not even the HP logo shows on my screen, for it remains Jet black as though it were turned off. The welcoming piano/keyboard intro-sound signifying it's on happens, and I even hear that airy "pop" which accompanies the little Java Update box that appears upon logging-on. Please, is there a combo of buttons with which I can revive my screen/picture?

• Answer:

  If it's a laptop, you may have accidentally set the laptop to use an external monitor. Look for a button (probably on one of the function keys along the top) that shows a picture of a monitor or says something like LCD/something. Press and hold your Function key (possibly marked Fn in the same colour as the pictures and often at the bottom left of the keyboard) and then press that monitor key. If it's a desktop, perhaps it has registry problems. I have seen this before; the computer booted up normally and we could hear it log in but the monitor went into standby mode partway through. (Unlike your situation though, we saw things on the monitor and then it would go blank.) You would need to get someone savvy to start it up in Safe Mode (you can try for yourself to see if that's possible) and if they can do that, they should then use something like Ccleaner to clean up the registry. http://ccleaner.com It should then boot normally. What has me puzzled though, is that you are getting an error beep code as the computer boots up and then it boots up anyway. Normally if there is an error and particularly a video error, the computer won't boot up. I'll have a poke around for what that beep code might mean and edit this if I find some more information for you. Meantime, add more details to give model details of your computer and what version of Windows you are running. EDIT: Sorry to be so long; the computer crashed and I couldn't find this question again (hadn't bookmarked it, slap on the wrist). Then I used Word today, which I'd forgotten I'd been using for info for you – I like Word's Recovered Document feature. :-) While I'm thinking of it, let me say well done for your observation and your clear and complete description of the problem. Those beeps are important and people often don't notice them or else don't give details on them. The model number was very helpful. It seems this is a common problem with Pavilions. It looks like it's a video problem and will have to go back to HP for repair. The good news is, it may still be under warranty because they extended the 12-month warranty to 2 years because of this problem. Although it's possible that you can get it working again by following some of the strategies I am giving you links to, some people have then had the problem resurface not long after. (No need to restart in between unless the instructions tell you to.) Don't do anything with RAM unless HP says to and gives you a job number. You may void the warranty. Don't worry about whether the instructions are for XP, Vista or 2000 – I picked the clearest. Things to test: Brightness On/Off lid switch Signal being sent to the laptop monitor and nothing interfering How: Follow the links I gave you and only do the headings I list. Try an external monitor and toggling between modes. LAST EDIT: I've just finished posting this and suddenly remembered, I could have found it again through my answered questions.... we can be such silly people sometimes!! ;-D