In fact, the main process of this problem is usually that after pressing the power button the fans they rotate for a few seconds, and in fact if there is LED lighting this also lights up for a moment, but soon after everything shuts down and the PC it won’t start and no matter how many times you try, the same thing always happens. Other times, the lighting and fans stay on, but the screen shows no image and there’s nothing you can do. If this is your case, do not despair, because we are going to tell you what you can do about it.
Why won’t my PC start even though the fans are spinning?
We must differentiate between two of the symptoms in order to narrow down what the problem is. If when pressing the power button the fans spin and the lighting turns on and stays on but the PC does not start, then there is a good chance that the problem is related to the RAM memory, the processor, the graphics card or the computer. the motherboard, in that order.
However, if after pressing the power button the fans start to spin and the lighting to shine but after a short time everything turns off by itself, then the problem is more likely to have to do with the power supply, the motherboard or simply because there is a short circuit somewhere inside your PC.
In both cases, we recommend arm yourself with patience because the problem can have a very simple solution, or it can be quite difficult to find the exact problem, and it may even lead you to discern that a component is failing and that you are going to have to buy a new one. to repair the PC. We are going to tell you next what you should do.
If the fans spin but turn off after a short time
This is the most frequently recurring symptom, and is usually preceded by a failed power supply or a short in the case, usually due to the case being bumped or moved or the equipment has been mishandled (for example, when cleaning the inside or installing new hardware).
The most direct way to solve this problem is, directly, to completely disassemble the PC and leave it “in the air”. It is advisable to use a multimeter or tester to check that the power supply is delivering voltages within the proper ranges before anything else, so if you want to start disconnecting and disassembling the power supply to check this first of all, as this is how you will immediately rule out that the problem is that the source has been damaged and that you have to change it.
If you check the power supply and determine that it works correctly, then it is quite likely that a short has occurred and as we said, the easiest (although laborious) way to solve the problem is to completely disassemble the internal hardware of the PC and reassemble it “On the air”, that is, mount the essential components (that is, everything except the box) on top of a box and see if that is how the equipment starts up. If it starts, there was indeed a short, so take the opportunity to clean the case and the rest of the components well and reassemble everything again, making sure that there are no loose cables and that there is nothing metallic touching the plate of the PC case .
If after doing this the computer still does not start, then either the power supply was broken or the problem is, potentially, in the power supply so if you have the possibility, try another. Otherwise, move on to the next section because you may have had even more bad luck.
If the fans and lighting stay on
When the fans and lighting stay on but the PC won’t boot, the first thing you should check is the RAM; With the PC turned off and disconnected from the power, remove the memory modules, clean them well as well as the sockets, reinstall them and try again. Oddly enough, sometimes the problem is solved just with that.
It is also possible that the computer is simply not getting a video signal, so the next thing to check should be the video connections from the PC to the monitor to see that everything is correctly connected (try changing the cable), that the monitor is turned on and that the input is in the correct option. Also check if the graphics card is powered on and if the PCIe power connectors are properly connected.
Also try to disconnect the graphics (obviously with the PC turned off), clean the PCI-Express socket on the motherboard and the graphics itself and reconnect it. If none of this works, try connecting the video cable of the monitor to the video output of the motherboard, because sometimes if the dedicated graphics is damaged, the PC automatically switches to using the integrated one.
Finally, it is possible that the worst has happened and that either the processor or the motherboard has gone bad; on modern motherboards, if the processor had failed, you would see an image on the screen indicating it, but on older motherboards this is not the case and the symptom is simply that the PC does not start up and that’s it. In any case, pay close attention to the beeps that the system emits when pressing the power button and consult the manual of your motherboard to find out what is happening.
Now, if the problem is that the motherboard is dead, unfortunately there is little you can do except change it for a new one.