My pc turn off automatically

Hi Miker,

 

You did not provide enough data for me to make an accurate diagnosis of your computer problem. I will however, give some insight into all the possible things that may have happened to it. Perhaps the span of 3-5 seconds is too short to give any description on your end. The following are just assumptions based on current troubleshooting methods. Actually most will just be answers to questions with anticipated solutions.

 

Does it show the POST when you start the PC within 3-5 sec., that it is powered? (A POST is boot information upon power up that shows the motherboard manufacturer, CPU clock speed, and memory diagnostics among other information).

 

If YES – some peripherals connected may be causing it to shutdown. Remove all peripherals connected like hard disk, floppy drive (if present), CD/DVD Rom drive one at a time. Then power up without the disconnected part. Take note which component causes the shutdown. If it goes beyond 5 sec on boot up without shutting down you have your suspect. Most likely culprits are hard disk drives.

 

If NO – If unit powers up with no display then shuts down it could be one of the following: A faulty memory module that could have bad contacts, a defective CPU, or a busted graphics card. Unseating the memory module and cleaning the copper contacts with metal polish should do the trick in most cases. Replacement could be an option if cleaning does not solve it. A CPU has a 25% failure rate in most cases. It’s the memory module more often than not. Unseated graphics cards also account for a third of the problem.

 

It could be that the Power supply module connected to the motherboard may be the cause. Low voltage outputs (12V, 5V, and 3.3V) respectively could cause it to shut down prematurely if not producing enough power to the motherboard.

 

If you are daring enough to open up your CPU casing then follow the guide to confirm if your power supply module is the problem.

 

Unscrew the power supply module fitted to the units casing. For tower type vertical units it usually is located at the rear portion (top part). Horizontal types have it at the sides (right or left side)

 

Acquire a digital or analog multi tester that has the capacity to read DC voltages. Follow the pin assignment here to give you an idea on how to measure voltages and what values to expect when measuring them. The Black part of the multi testers prod is the negative one (-), usually color coded as black, and the Red part is the positive (+) one. Take note of the polarities as you do the test since an analog meter needle tends to go to the opposite direction when test prods are reversed (+ to – or – to +). It should be + to + and – to -. Digital meters just show an indication that the prods have reversed with no grave effect.

 

If the measured values don’t match the pin assignment voltages they were supposed to read then it means the power supply module is at fault and needs to be replaced. If voltages are all normal, then it’s a problem with the motherboard.

 

In conclusion, one quick thought to ponder is that when a PC shuts down after a few seconds it means that the safety feature of either the motherboard and the power supply activated itself to prevent damage to other circuit components of the system. It is up to the troubleshooter to pinpoint the faulty part by the process of deduction.