Among the many ways that a computer won't turn on, a complete loss of power is rarely the worst case scenario. There is the chance that your PC isn't receiving power because of a serious issue but it's unlikely.
There are several reasons that your computer won't power on so it's very important that you step through a complete troubleshooting procedure like the one I've outlined below.
Important: If it appears that your computer is in fact receiving power (you see lights on the computer case, fans are running, etc.), see my How To
Troubleshoot a Computer That Won't POST / Turn On guide for a more applicable guide.
Difficulty: Average
Time Required: Anywhere from minutes to hours depending on why the computer isn't receiving power
Here's How:
1. Believe it or not, the number one reason why a computer won't turn on is because it wasn't turned on!
Before starting a sometimes time consuming troubleshooting process, make sure you've turned on every power switch and power button on your computer:
- Power button/switch on the front of the computer
- Power switch on the back of the computer (power supply)
- Power switch on the power strip, surge protector, or UPS (if you have one)
Examples:
"I spent ten minutes trying to figure out why my computer wasn't coming on before I realized that I hadn't flipped the power switch on the surge protector that my computer was plugged into!"
2. Verify that the power supply voltage switch is set correctly. If the input voltage for the power supply does not match the correct setting for your country, your computer may not power on at all.
3. Check for disconnected computer power cable connections. A loose or unplugged power cable is one of the top reasons why a computer doesn't turn on.
Check the Power Cable Behind the Computer Case
Power cables often wiggle loose from PC cases over time or sometimes after being moved around. Checking every point where electricity is delivered to the computer system is usually a first step when a computer isn't receiving power.
The first place to start is with the power cable that connects at the rear of the computer case. The power cable should fit firmly in the three-pronged port on the power supply.
Verify PC Power Cable Is Securely Plugged In
Follow the power cable from the back of the computer case to the wall outlet, surge protector or power strip that it is (or should be) plugged in to.
Make sure the power cable is securely plugged in.
Verify Power Strip Or Surge Protector Is Securely Plugged In a Wall Outlet
If the power cable from the PC case was plugged into the wall outlet in the last step, your verification is already complete.
If your power cable is plugged into a surge protector or a power strip, ensure that it is securely plugged into the wall outlet.
4. Perform a "lamp test" to verify power is being provided from the wall. Your computer isn't going to turn on if it's not getting power so you need to make sure that the power source is working properly.
Note: I don't recommend testing an outlet with a multimeter. Sometimes a tripped breaker can leak just enough power to show proper voltage on the meter, leaving you with the assumption that your power is working. Putting a real load on the outlet, like a lamp, is a better option.
5. Test your power supply. At this point in your troubleshooting, it's very likely that the power supply unit (PSU) in your computer is no longer working and should be replaced. You should however test it just to be sure. There's no reason to replace a working piece of hardware when testing it is fairly easy.
Exception: An ozone smell or very high pitched noise, combined with no power at all in the computer, is an almost certain indication that the power supply is bad. Unplug your computer immediately and skip the testing.
Replace your power supply if it fails your testing or you experience the symptoms I just described.
Important: In the majority of cases when a computer isn't receiving power, a nonworking power supply is to blame. I bring this up again to help stress that
this troubleshooting step should not be skipped. The next few causes to consider aren't nearly as common.
6. Test the power button on the front of your computer's case. It's not a very common point of failure but your computer might not be receiving power because the power button on the front of your PC is damaged and is not actually turning your computer on.
Replace the power button if it fails your testing.
7. Replace your motherboard. If you're confident that your wall power, power supply, and power button are working, it's likely that there is a problem with your PC's motherboard and it should be replaced.
Note: While perfectly doable by anyone with some patience, replacing a motherboard is rarely a quick, easy, or inexpensive task. Be sure you've exhausted all of the other troubleshooting advice I've given above before replacing your motherboard.
Note: I highly recommend that you test your computer with a
Power On Self Test card to confirm that the motherboard is the cause of your computer not turning on at all.
Power On Self Test Card
Tips:
Are you troubleshooting this issue on a PC that you've just built yourself? If so, triple check your configuration! There is a decent chance that your computer isn't powering on due to a misconfiguration and not an actual hardware failure.
Did I miss a troubleshooting step that helped you (or might help someone else) fix a computer that's not showing any sign of power? Let me know by sending me a PM or reply to this thread so that we could share this to fellow istoryans that need our help. I'd be happy that you include additional information here.
Is your computer still showing no sign of power even after following the steps above? Let a community of computer support enthusiasts help out! Post the details of your PC power problem in this thread.
Be sure to tell us what you've already done para di mag balik2x ang tubag / suggestions on what to do
How To Troubleshoot a Computer That Shows No Sign of Power
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