Steps to fix the computer not showing up

Hi guys, when I received the case, it didn’t show up, I clicked on the power button and it didn’t start up or the machine just beeped on the speakerphone. Here, I will guide you through the steps to fix a computer that doesn’t show up for new computer technicians.

I will divide it into 2 cases: Pressing the power button the fan does not spin, and pressing the power button the fan rotates but does not show up.

+ Case: Press the power, the fan rotates but does not show up.

First of all, when you receive the case that the machine does not start up, you need to ask the customer carefully what is wrong with the machine, when, when it is using the device or due to an electrical short… Asking carefully will help correct the disease and faster. For example, if a customer says there is a short circuit, we will think of the power supply, if rain water hits the case, we will think of the mainboard being touched by water…
Try plugging the client’s case into your monitor, to rule out screen failure, or a problem with the power supply at the customer’s home.
Open the case and remove peripherals such as DVD drive, LAN card, Hard drive (the hard drive is the most important, because when testing the machine, just plug it in and then pull it out many times to burn the hard drive -> lose data. ). Then plug in the power and press the power button to check if the machine turns on. Remember to plug the VGA cable into the correct VGA port on the machine, some machines attach a separate video card, when we plug the monitor wire into the onboard VGA port, the machine will not show up. In addition, it is necessary to add a keyboard to know if the machine is up or not by pressing the num lock key to see if the light is on.
The machine still does not turn on, see if you have a discrete and onboard video card. If the machine has an onboard VGA but the customer uses a separate video card, then you can remove the card and attach the wire to the onboard VGA port. Usually do to this step, the machine is up, because most of the diseases are caused by the long-term use of the video card, or the chip is dead.
The machine still does not turn on, then you remove the Ram completely, attach the external speaker. Should buy a motherboard test card will diagnose faster. Then click on the power and listen to see if the external speaker sounds “tick ! tit ” to report a ram error, or the main test card has jumped a few codes. If yes, then the fault lies in the Ram, try another Ram is OK.
The machine still does not sound at the speaker, the disease is worse, you still leave it, but try another source, just plug in the 20 pin (or 24 pin) jack and 12v jack and then turn on the power again. If the machine beeps, replace the power supply and you’re done.
Removed all peripherals, removed Ram, tried another source, but still nothing. Now you remove the CPU fan completely, remove the CPU holder and mount it up and down a few times => the purpose is for the CPU to contact the socket pins. Because it can be used for a long time, dirt and dust can make contact with the legs not good, because of the cleaning process of attaching the FAN to the latch, it takes a while for the CPU to be on one side. Or the machine is used for a long time to open the ball lead at the foot of the socket.
After 6 steps on the machine still not up, you completely remove the mainboard to test. Because it can be due to tightening screws, changing ram, removing the FAN and then pressing it down too hard, making the machine not touch the mass. If it is up, you assemble the mainboard into the box according to the correct operation in the article: Note when assembling the machine into the box .
Finally, check and repair the mainboard, maybe because the capacitor is dry for a long time, dead ic ram, chipset …

+ Case: Pressing the fan button does not rotate.

Remove the peripherals and then click again. There are many cases where the hard drive is burned, the LAN card or the sound is short, and the power cannot be pressed.
The power button itself is damaged, or the wire connected to the power button is bitten by the mouse. The power button pressed many times too hard to break the leg, so it could not contact the power cord on the mainboard. You completely remove the P.ON power cord connected to the mainboard panel and click it directly on the mainboard by using a screwdriver or tweezers to touch it.
Due to short circuit, dry capacitor, loss of voltage to the P.ON pin, replace the good source to rule out this case.
The last step is because the mainboard is shorted, 32,768 KHz quartz dead, mosfet short, Vcore short or dead chip Nam, IO chip. We just need to check and fix the mainboard can’t get the source.