Case fans wont power on

[jhug87]

Hi, I built my current computer about 4 or 5 years ago, and have been upgrading it along the way. A couple of days ago I noticed all of my case fans (and LEDs including the fan speed controls on the case) would power off for a few seconds then power back up. Nothing changed with anything else. Well now the fans won't come on at all. The computer is still running fine. The case fans just arent working.

The current power supply is about a year old, a 750watt corsair. The motherboard I just replaced a few months ago after the old one died. I'm not really sure what's causing the problem. Any suggestions are appreciated.

 

[SkyNetRising]

So you're using fan speed controller, right? How many fans btw?
What happens if you connect fans directly to motherboard (without fan speed controller)?

 

[Paperdoc]

If all your fans are plugged into that controller built into your case, and all of them have done exactly the same thing, the controller is the problem. But a common type of problem is simply that a connection is loose or has become dirty so the electrical contact is poor. Find the wires from that controller unit that go to the PSU to get power. Inspect them for looseness. Then disconnect and re-connect a few times, and this may "scrub" surfaces clean. You may want to do the same for the place where the fans connect to the controller.

Last related possibility is that the switch (es) inside the controller have developed dirty contacts. Sometimes if you're lucky, just sliding the switch(es) back and forth will fix the problem, even temporarily. If it does, you know that switch is the source of your trouble, and you'll need to figure out a permanent fix.