One thing must be taken into account, and that is that if you turn on the PC and it is only a fan that does not work, the most likely thing is that the problem is centered precisely on said fan; However, if all the fans are not working, then the problem is much more serious and probably does not have to do with the condition of the fans themselves (it is quite a coincidence that all the fans of the computer will break down at the same time, not?).
Why can this problem happen?
The problem can be caused by several reasons, and it will depend on how you have the fans connected since it is not the same that you have all the fans connected to motherboard to use a bus or fan controller such as a Corsair Commander or other integrated control device in the equipment box.
The problem can be caused because the PWM controller of the motherboard, in case you have the fans connected to it, has been damaged or simply misconfigured (in which case it has a solution), but it can also be caused in the case that use a fan controller because it has broken, because it does not get power, or even the PC fans may not work simply because there is some kind of short in the case, something more common than you think.
If you turn on the PC and the fans do not work, the first thing you should think about is whether it was because, or was it due to making a software and / or hardware change, or because you have accidentally hit or moved the PC case. Something like this can also happen when installing a control software such as Corsair iCUE or NZXT Cam, since although these programs are designed to control their own hardware they can detect third-party hardware as well and have the fans set to zero speed initially until you configure them. by hand.
What to do if the fans don’t work
As we told you a moment ago, the first thing you should do is remember if you have made any recent hardware or software changes, as well as if the PC case has recently been moved or bumped. We are going to see the symptoms one by one and what to do in each case, starting with the software changes.
There are many specific programs for hardware monitoring and control, such as the examples that we have given you of NZXT Cam or Corsair iCUE. Imagine that you have installed a new Corsair fan on your PC and after installing iCUE and rebooting, the fans have stopped working. You should go into the software settings to see if it is trying to control all other fans and if they are stopped as a result of this software.
Continuing with the software, you should also access your computer’s BIOS by pressing DELETE or F2 (depending on the model of motherboard you have) when starting the PC if your fans are connected directly to the motherboard.
Once in the BIOS, go to the section “PC Health Status” or similar where you can control the configuration of the fans and there check first if the motherboard is detecting them, and second if they are configured to work or to be stopped. This configuration depends on the motherboard and if you use BIOS or UEFI, but in any case you should find parameters to control and monitor the operating parameters of the fans connected to the motherboard.
In the event that the motherboard does not detect a connected fan, there is a good chance that the PWN configuration has been messed up, but do not despair because there is still something you can do about it: reset the BIOS to factory settings. For this you can do a Clear CMOS, but we would personally recommend you to use the method of removing the battery.
To do this, turn off the PC and unplug it from the power outlet, wait at least 2-3 minutes for it to fully discharge, and then remove the battery. Wait at least 10-15 more minutes and, in the meantime, we would recommend taking the opportunity to disconnect all the fans from the board, clean the connections a bit, and reconnect them where they were. Then put the battery back in, plug in the PC and turn it on again to access the BIOS again and see if the fans now appear.
If after doing this the motherboard still does not detect any of the fans, then it has probably been damaged and to fix it you will have to either change the motherboard or use a fan controller.
In light of the latter, as we have mentioned, it is possible that this is precisely the culprit that the fans do not work. If the fans do not work when the PC starts up and you have a controller, check that all the connections are correctly connected (we recommend that you disconnect everything and reconnect it to make sure), placing special emphasis on the power supply since these controllers generally use a SATA connector or MOLEX from the power supply to run. If after doing so it still does not work, try changing the power connector of the power supply to another, lest the cable or the connector itself has been damaged.
If the fan controller is built into your case as is the case with many models, check that the switch is in the run position. Try moving it in its different positions to see if the fans turn on when you do so, since there is also the possibility that the switch is the cause of the problem.
Finally, you should check that a short is not occurring in the PC case. There are times that metal ties are used to tie the cables, and if a metal point is making contact with the case plate it can cause a short circuit that causes irregular operation in the PC, such as causing the fans not to work (because the short is affecting the controller, precisely).