Other What kind of LEDs to choose for power button LEDs?

[Mortis Angelus]

One last thing I need to do to finish my Xbox-build is to fix the power-button LED, as I could not get the stock LEDs to work without short circuiting the board --> causes the entire PC to just shut off. The PCB to which the power button and LEDs are soldered seem to be made so that all circuits are connected. I get the same issue if I try to convert the smaller button as a reset button.

So my question is simple; what kind of LEDs can I use (Voltage, Ampere) as I would just hook them up straight to the the power pins on the motherboard next to the on/off switch on the motherboard.

 

[smitty2k1]

motherboards output 5v for the power and HDD LEDs. However, a lot of the aftermarket power buttons people use (look up Ulincos) are 12v LEDs. However, because the motherboard only outputs 5v, they run a little dimmer, but still bright enough.

 

[Mortis Angelus]

motherboards output 5v for the power and HDD LEDs. However, a lot of the aftermarket power buttons people use (look up Ulincos) are 12v LEDs. However, because the motherboard only outputs 5v, they run a little dimmer, but still bright enough.

So the take home message here is basically, I can use anything as long as it is rated for 5 V or higher? Anything lower will burn up.

How many ampere should I go for? Or is that not important?

 

[Thehack]

So the take home message here is basically, I can use anything as long as it is rated for 5 V or higher? Anything lower will burn up.

How many ampere should I go for? Or is that not important?

Not important. If amperage was important you're looking at LED used in flashlight.

Just get a regular LED+switch combo. They come in 5-6V flavors that will work.

 

[QinX]

TL;DR
Likely any single LED will work and take about 20mA of current.

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Looking at my motherboard I did a quick measurement on the switch I've got connected.
without the LED connected I'm getting 5V out if it.
With it connected I'm getting 2.7V

It might be different from board to board, but it seems a simple constant current source circuit is used.
Likely maxing out at 20mA.

So regardless of what's connected the voltage is lowered to the point that the LED is using 20mA and the corresponding voltage required to reach 20mA.

based on that using a 12V LED will either not work or be extremely dim.
Connecting a piece of 12V LED strip at least doesn't light up on my end.

So the take home message here is basically, I can use anything as long as it is rated for 5 V or higher? Anything lower will burn up.

Anything under 5V is guaranteed to work, anything over it might not/be dimmer than expected.