When I boot up, monitor turns on, then a few secs later shuts off.?
922212
We had what we thought was a dead monitor at the library I work at.  Turned out that the vga connector into the CPU was loose.  The tech jiggled the connection and the monitor came back on.  Hope I explained it correctly.
973133
Black--or blank ?  \n\nIf it's black, then It sounds as if the power saver function might be on the fritz.\nUsually, striking a key or wiggling the mouse brings the last image on the screen back up.  Does the monitor have a small light on the front that is green when the screen is active? If that light turns yellow when the screen goes black, that tells you that the power saver function is on.  \n\nIf it's blank [not black], then I don't know what to tell you.  Call tech support and try not to lose your temper with the overseas representatives.
1148876
It is possibly overheating. Check the fan. Check power supply, it could be going out. If not:\nYou probably need to reorder your BIOS by hitting del on startup. If you dont know how to do this please dont try, get help first.\nHere is a search of this problem, choose one of these forums that seems most similar to your system and ask them. They should be able to help. Its hard to troubleshoot a problem on Yahoo Answers as we cannot easily have continuous dialogue.\n\nGood Luck!\nhttp://www.google.com/search?hl=en&q=computer+restarting+over+and+over
3604
It could be your video card has died.  Or try a new monitor cable.
328960
sounds like either the monitor cable is unpugged to the back of the monitor or the CPU or the video card is dead.
823795
Did you see anything at all when you boot up the computer?  Things like BIOS settings/ Chipset.... that would generally show up on the monitor.  Maybe the resolution setting is much more than what your monitor can handle.  Reboot and log in Safe Mode and lower the resolution.
982473
What you are in need of is called a Bios Debug Card.  You can get a cheap one from Soyo at http://www.geeks.com  Is your CPU fan plugged in right?  Most newer boards will not start up if that is not working.  If it is working when you power up, but are not getting any video the video card may be bad.  If nothing is working but you are getting beeps on Boot, then the RAM may be bad.  A good rule of thumb is to try using only the main components (video RAM Hard drive) and get the system running first.  Then start adding other components (sound network modem etc) after it is running.  This helps stop any conflicts from happening when you first try to get a system running.  Hope this helps
744801
could be a power supply or overheat issue
752978
Check that the monitor cable is correctly connected.\nIf it is, then get a new monitor from some place with a good returns policy - just in case the problem is with your graphics card!!
691468
need more info than that to diagnose.  make sure your cables are plugged in tightly?  is the jumpers on the hard drive on the correct pins?  can you hear it booting up. when does it stop?\ntoo many variables
636654
Because you have already checked if anything was overheating.\nI would check if the ram.\n\nIf you have two sticks of ram installed try booting with just one. Of course test both of them.
363560
I had this problem before, I fixed it by reseting the bios to it's defaults, unfortunately I never did find out exactly what bios setting was causing it though. You can take a look under the "power management" section of your bios and see if you can find it, or just do like I did and reset it to defaults.
117268
Check the cabling between the monitor and the PC. It may be a bad connection.
958302
yea this has happened to me before i think it has to do with your power supply, is this an older PC?  Pretty sure its the power supply shorting out a Lil and making it think its restarting
802225
It depends does it immediately go away and come on when the computer is booted?  or does it not come on at all?  \n\nSometimes it could just be a loose connection.  At my old job we had a monitor that would come up with no input found...once the computer finished booting the monitor was fine.  Sometimes I think it just takes a minute for the monitor to catch up with the rest of the machine.  Hope this helps some, some additional details and proper grammar when asking a question like this would be helpful.
810118
You're going to have to supply us with a lot more information - is it plugged in?  Is your computer on?  Do you have the right cable?  Has the monitor worked before with other PC's?  Have other monitors worked with that PC?
1024825
Is there anything on the monitor when you turn it on or is it just completely black?\n\nIt could be a number of things. It could be your fan or your connection or maybe your RAM is damaged. Normally if your hard drive or memory dies, you would not be able to turn the computer on at all or you get a message on your monitor saying an error occurred trying to read your drive.\n\nI have an emachine too, I usually do my own fixes, but I would open the motherboard up and watch what the circuits are doing when you try to turn it on. If you had a short circuit from a power outage and you dont have a surge protector, then its possible it damaged your hard drive or your memory.\n\nEDIT: Yes, 4 years is usually the lifetime of a desktop computer, especially an emachine. You will have to take it to the technician and figure out whats wrong with it because I read the other DETAILS and it sounds like your hard drive has fried or some part of your motherboard has been damaged. You will need to install a new hard drive. Normally when your hard drive gets fried, the data is not retrievable. A technician can tell you whether or not they can save the data, but it will cost you A LOT trying to recover all your data from your hard drive. You should always backup any important data every few months to a CD-RW in case this stuff happens. A computers lifetime is very random, but 4 years is usually when something goes wrong.