If you are in this bracket then you might be facing a malfunctioning or at worst a dead Power Supply Unit or PSU, these days Switch Mode Power Supply or SMPS are used aswell.
- System start-up failures or lockups: If your PC is not booting up even if you have pressed the power button with the monitor etc powered on or the boot up process halts/freezes mid way then you need to check your PSU for sure.
- PC takes a long time to shut down or Boot up: A noticeable change rather increase in the time that your system takes in booting up or shutting down is a very strong indication that the power unit is the culprit.
- Spontaneous rebooting or intermittent lockups during normal operation.
- Memory Errors: Your system shows memory allocation or process execution error multiple times quite frequently even during day to day work.
- Hard Disk Drive (HDD) fails: If you experience a total freeze and have to shut down the system by manually pressing the button followed by a no red blink of the LED on the cabinet then your HDD just stopped spinning telling you that it didn't receive the power required hence your PSU failed.
- Fan is not spinning: The fan just stopped spinning along with a over heated PC! That's a real bad news, shut it down quickly and get a new Power Supply for yourself.
- USB devices are not working: Especially those that rely on the USB port for power like an external HDD or a cell phone and even memory cards. Also you may experience a sudden freeze of operations on your system when you plug in these devices.
- Electric shocks that are felt when the case is touched
- BIOS beeping codes detected: This you'll face during the booting process when the computer POST, it'll beep multiple times and finally boot up or it might not even showing that their is insufficient power.
- Smoke: You see a little or lot of smoke coming out of your system that's an indication of over heating and a faulty power supply can strongly be the root cause.
Always choose a good PSU/SMPS for your system so that it stays stable and can power all your components. I hope this article served your purpose, for any other query or to add something more to this article that I might've missed upon ,do leave a comment.