Why are the LED lights on my fans not working

pp_hurtz

Junior Member
Sep 13, 2019
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I have had this pc for like two weeks and the fan LED's were working fine but all of a sudden when i get home and turn on my pc the LED's don't work but the fans are still on
 

aigomorla

CPU, Cases&Cooling Mod PC Gaming Mod Elite Member
Super Moderator
Sep 28, 2005
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3,174
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possible the LED's blew out.

Try them on another header port to rule out bad header.
 

mindless1

Diamond Member
Aug 11, 2001
8,028
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What make/model of fans? Are the LED electrical contacts exposed or at least accessible so you can use a multimeter to check the circuit? Do you have a multimeter?

Is the fan on a fan controller or motherboard controlled header that varies the speed? The LEDs are "probably" in series with a resistor and a voltage too low could cause them not to light up at all, not just be dimmer similar to how the fans might get slower with a lower (average if PWM) voltage. Then again I expect you would have noticed that on a new build, before two weeks passed.