I'm building a case from scratch and have a question about the power and HDD LED outputs on the motherboard. I've inspected a few cases and and I don't see any inline resistors on the front panel LEDs. I was assuming the power and HDD LED pinouts provide 5V so are these special 5V LEDs? Can anyone confirm the voltage provided by motherboards for these LEDs?
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front panel LED voltage
- Thread starter matman
- Start date
Some googling tells me that the LED outputs are 5V and have a current limiting resistor in the motherboard. That apparently means you can plug in any LED and it will be fine but maybe not optimally bright. I'm not entirely convinced because a very long time ago I once melted the insulation off a reset switch by plugging it into a power LED output...
- Joined
- Nov 24, 2013
- Messages
- 889
Id check the pin output voltage with a meter first to see what its really providing
Got it, yeah I could check this. If there is a current limiting resistor wouldn't that affect this though?
If there's a current-limiting resistor on the motherboard, but no LED connected, then you'll see the full 5V at the pins.
In every computer I've seen, the LEDs are connected directly to the MB, so there's gotta be a resistor on every MB. You'll be fine hooking the LED straight to the MB.
In every computer I've seen, the LEDs are connected directly to the MB, so there's gotta be a resistor on every MB. You'll be fine hooking the LED straight to the MB.
Great, good to know. I figured this would be the case... Hopefully I don't burn out the LED!
