This is a pretty tough problem to track without actually seeing the set-up... Also difficult to pin down because you're going blind...
John_boy and 12m8keall2c gave the replies that came first to my mind as well... Most often the problem is that your computer hardware has not been
installed correctly, your motherboard's jumpers are set incorrectly, your BIOS settings are not correct, or your computer or peripherals have been
shorted out and/or have some other mechanical problem.
First (and you've probably tried this already) is check that the monitor is actually working. Test the screen on another PC to check that it's
working, and you can even test another screen on the PC you want to get working.
Important information you might be over-looking is the BIOS startup test/POST (Power On Self Test)... When you start the PC, what is the beep sound
during the first few seconds from the internal speaker? Is it a long beep, a single short beep, several beeps, etc? This is important because the PC
might be telling you what's wrong.
is a list of the beep codes and the problem they're indicating...
If that doesn't help you I would suggest that you carefully go through everything inside the PC, part by part...
1. Check and make sure all cables are firmly attached to the back of the computer and to all external devices. Retry.
2. Remove the case cover from the computer. Make sure all cables (hard drive, power cables, other disk cables) inside the computer are firmly
Press down on all ISA and PCI cards and make sure they are firmly seated. Make sure your DRAM memory cards are firmly seated. Feel the top of the CPU
and make sure it is not hot (warm is OK). Retry.
3. (This step is usually for newly built computers that have not successfully booted.) Get out your motherboard manual, or download one from the
manufacturer's site, and go over all your motherboard jumper settings.
Set the jumpers in the most conservative position. Review all your accessory wire connections (keyboard lock, hard drive access light, etc.) and make
sure the connectors to the motherboard are facing the same direction. Retry.
4. Turn the computer back on with the case off. Verify that your CPU and power supply fan are running. If either one is not running you have a
problem. If the power supply fan is not running replace the power supply (make sure the power connectors are correctly attached to the motherboard).
Make sure the CPU fan is connected to power on the motherboard. If it is correctly connected and still doesn't run, replace it. Retry.
5. Unplug your computer. Remove all PCI and ISA cards. Reinstall the video card and disconnect the hard drive cable. Plug in the keyboard, video
cable, and power cable. Restart your computer. If this worked, go to Step 6. If your DOS screen doesn't come up at this point try the following
a. Closely examine your motherboard and make sure it is not making contact with the computer case, which will short it.
b. Your video card, video cable, or monitor may be malfunctioning. Borrow a video card, cable and monitor, retry.
c. Remove and reinstall your DRAM. If your computer can not find system memory it will not POST.
d. Remove the CPU and reinstall it.
e. Follow your motherboard manual's instructions for resetting your BIOS to its default configuration.
6. If you now have a DOS screen on your monitor, attach your hard drive cable and reboot. Make sure the hard drive is correctly set up in the BIOS.
Press the Delete key during the POST memory check to enter the BIOS. If your hard drive doesn't work, you have incorrectly attached the drive ribbon
cable or power cable. See our article Installing a Second Hard Drive for the correct procedures for installing the hard drive ribbon cable.
7. Add your other PCI and ISA cards back into the computer one at a time. Reboot after each card is installed to make sure the new card isn't causing
Quite a mission.... Good luck!
[edit on 13-2-2006 by Gemwolf]