power LED is not lit, computer's working

[cL0N31]

my previous computer i built from a barebone, meaning that i bought case+mobo+psu in one shot... needless to say that all the wires from psu and case were connected to the mobo by manufacturer so i didn't bother messing around with them... this kind of setup served me right about over 3 years, during which the pc was working constantly almost all the time with relatively few power offs... it means that power LED (blue colored) was almost always in the ON state for that period of time...

recently (a few weeks ago) i installed the new mobo with the new everything into same old case mentioned above... connected everything on my own and the power LED was lit and everything was fine... yesterday the power LED stopped lighting, however everything is working... in my understanding 3 years for an LED is nothing... could it be the cause that the new mobo supplies a different voltage to an LED or something like that? please, let me know what's the deal here

[Nelson37]

Connections and voltages are standard, either the wire slipped off or the LED failed. IT works, no worries.

[creakndale]

Blue LEDs are susceptible to Electrostatic Discharge (ESD) damage and latent ESD damage. Red, Yellow and Green LEDs typically are not. You could try connecting one of the other case mounted LED's onto the motherboard pins where the blue LED was connected (like the HDD activity LED). LED's are polarity sensitive. Anode is plus. Cathode is minus.

[cL0N31]

Nelson37: wire didn't slip off, why did it fail then?

creakndale: yes, it's a blue power led... it failed while working, could the esd be the cause in this case? add: just checked whether it's from a mobo, no - the mobo is fine... the LED is probably dead but i can't understand why it died... it shouldn't

[Midzuki]

the LED is probably dead but i can't understand why it died... it shouldn't

It shouldn't, but apparently it did. The average/estimated lifetime of a LED is just that ---
an average or estimated numeric value. The actual "mileage" of the individual devices may vary ---
and it does. There are LEDS that work during years, and there are LEDs that will last only for some hours. Better go to the shop next corner and buy some new ones --- they are not that expensive.

[redwudz]

I've replaced them using a 'hot' glue gun' to hold them in place. I would switch the LED from the HDD temporarily as mentioned. That would tell you the motherboard is OK. If you have a computer shop around there somewhere, they may give you a LED from a junk case with the leads already attached. Much easier than attaching a new one to the end of the present cable.

Just pop off the case front face and you should have access to the LEDs and mounts.

[Nelson37]

A failed LED does not affect the operation of the PC in any way whatsoever.

In all the lightning strikes, surge and brownout damage events, power supply failures, motherboard failures, and any and all PC component failures I have seen in 20 years, I have never, ever, seen or even heard of a situation in which an LED failure was either caused by, or an indicator of, some other more serious probloem.

IMO it is a 10 cent part which is not worth the time or hassle to worry about, much less repair.

The hard drive LED is significantly more useful in managing your PC health than the power LED. You know you have power when the machine boots successfully.

As for why it failed, perhaps there were several electrons which were mis-aligned by a few angstroms. Perhaps it was made on a Monday. WHo knows, and who cares? This is just not something to be concerned about, though it is easily fixed if it really is bothering you. There are just so many other useful things which you could cpend your time and effort on.

[minidv2dvd]

led's are sensitive to the polarity. the + and - may be connected wrong, turn the connector the other way.

[creakndale]

Here's a good description of why LED's fail.
http://www.emsnow.com/cnt/files/White%20Papers/DFRLEDFailures.pdf

[redwudz]

While LEDs are sensitive to polarity, on a motherboard the current and voltage supplied to them is well regulated. You can hook them up backwards in that application with no apparent damage. They just won't light.

One of my Antec cases has four front LEDs. Power, HDD and two auxiliary LEDs. I have never used the two auxiliary LEDs, though I would really would like to port the LAN adapter indicators to the front.

I've replaced a couple of front power indicator LEDs. My suspicion is that they were hooked to terminals on the MB other than the front panel indicators. Blue LEDs, especially the early versions did have a higher failure rate than the common red LEDs. The blue LEDs I've seen also operate at a slightly higher voltage than the common red LEDs. And they are more sensitive to static discharges.