The most common way a computer “won’t turn on” is when the computer does turn on, but doesn’t display anything on the monitor. You see lights on the computer case, you can probably hear the fans running from inside, and you might even hear sounds, but your screen doesn’t display anything at all.
How to fix a computer that turns on but doesn’t display anything
Try these common fixes in the order we present them:
1. Check your monitor. Before you get into the more complicated and time-consuming troubleshooting of the rest of your computer, make sure your monitor is working properly.
After disconnecting your monitor from your computer, turn it on and off. If the display shows any diagnostic information, you know that the display is on and capable of displaying content.
2. Make sure that your computer is completely restarted and turned on from a completely off state. See how to restart your computer if you need help.
Your computer may appear to be “off” when in fact it is just having problems getting out of power-saving mode in standby/sleep mode or hibernation in Windows.
3. Eliminate the cause of the beeping code if you are lucky enough to get one.
The beeping will give you a very good idea of exactly where to look for the cause of your computer shutting down.
4. Clear the CMOS. Clearing the BIOS memory on your motherboard will reset the BIOS settings to the factory defaults. Incorrect BIOS settings may be the reason why your computer won’t start up completely.
5. Make sure that the power supply voltage switch is set correctly. If the power supply input voltage is incorrect, your computer may not fully start.
There is a good chance that your computer will not start at all if this switch is incorrect, but an incorrect power supply voltage can also prevent your computer from starting properly in this way.
Reinstall everything possible inside your computer.
6. Reinstalling will restore the various connections inside your computer and is very often the “magic” solution to problems like this one.
Try reinstalling the following components and then see if your computer displays anything on the screen:
- Reinstall all internal data and power cables
- Reinstall the memory modules
- Reinstall any expansion cards
- Reinstall the CPU only if you suspect it may have come loose or been installed incorrectly.
Check for signs of shorts inside your computer. If you find them, you’ll need to find out the causes of those shorts.
Check your power supply. The fact that your computer’s fans and lights are working does not mean that your power supply is working properly. The power supply tends to cause more problems than any other equipment, and is often the reason that computer components work selectively or intermittently.
Replace the power supply immediately if it fails any test you are running.
Run your computer only with the right equipment. The goal here is to remove as much equipment as possible while still maintaining your computer’s ability to turn on.
For example, disconnect peripherals that are not needed for your computer to function properly, such as storage devices connected via USB.
If your computer starts normally with only the necessary hardware installed, skip to step 11.
If your computer still does not display anything on the monitor, go to step 12.
Reinstall each piece of equipment you removed in step 10, one at a time, checking after each installation.
Since your computer is on with only the necessary hardware installed, these components should work properly. This means that one of the hardware components you removed is causing your computer to not turn on properly. By installing each device back on your computer and testing them each time, you will eventually find the hardware that is causing your problem.
Replace the faulty hardware as soon as you identify it.
Check your computer’s hardware with a power-on self-test board. If your computer is still not displaying information on a monitor that has anything other than the main computer hardware installed, the post card will help you determine what part of the remaining hardware is causing your computer not to turn on completely. If you don’t have and don’t want to buy a postcard, go to step 13.
Replace each piece of major equipment on your computer with an identical or equivalent replacement piece of equipment that you know works, one component at a time, to determine which piece of equipment may be faulty. Test after each hardware replacement to determine which component is faulty.
If you don’t have a postcard or replacement parts to replace and replace, you are left in the dark as to which part of your main PC hardware is faulty. In these cases, you have little choice but to rely on the help of individuals or companies that do offer these resources.