Unplugthe computer and hold the power button in for 10-30 seconds. Usually you will hear a popping sound when the MB discharges. If that doesn't work, unplug the 24-pin connector from the power supply to the motherboard. Again, you will hear a pop when the motherboard discharges. Checkif the power supply (PSU) has a button to cut the power to the machine. Check if this button is in the position denoted with ON or I. Check if EVERY power cable is plugged in securely, reseat if necessary. Check if the power button is installed correctly (consult your motherboard manual) computernot turning on. Thread starter toppersx21; Start date Dec 23, 2017; Toggle okay so when I turn on my power supply my mobo light up. but when I go to hit the power button on my case I hear a little noise that doesn't sound good. but nothing power on. not my gpu my fans nothing If it is ok then 2nd is to check your mobo. Upvote 0 Checkthe video guide to know how to troubleshoot laptop power issues that may prevent your laptop from turning on. SHOP SUPPORT. PC Data Center Mobile: Lenovo Mobile: Motorola Smart Turnoff the computer. Disconnect the power cord from the PSU, and wait for 15 seconds. After 15 seconds, connect the power cord back to the PSU. The LED light should stay on for 3 seconds and then turn off. If the built-in self-test LED turns on, then the power supply unit is able to deliver power to the system board. Quicktest to see if it's HDD or OS failure, rather than (other) hardware, e.g., loose connector or power supply. Hold down the key to go to BIOS/UEFI, and then turn on the power with the power button. If the monitor still shows nothing, it's hardware failure. - DrMoishe Pippik. Ifthe issue persists, follow the below steps: Step 1: Remove discs and devices. Before troubleshooting startup issues, remove or disconnect all discs and devices from the computer. Turn off the computer. Remove any discs and USB devices. Remove memory cards from the card reader slot. Powercycle the computer. In some situations, a computer may have power related issues often caused by either the power supply or the motherboard. To help determine if this is the issue, try turning the computer on, off, and back on as fast as possible, making sure the computer power light goes on and off. PSUSupercomp SEP 500 The PSU is fine,i tested it on my friend's pc I am guessing its the motherboard,but i dont know why it will suddenly stop working cause i took good care of it Ittakes full power removal to get it restarted. Removing the AC power allows the voltages to bleed off and get all devices back to the start point. It only takes a residual amount to keep the J373ZO.