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On the hdd led, reset swith, soft power connector, is the white or the colored wire negative?

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As and pointed out, there is a common color convention (colored = positive, black/white = negative), but it is only a convention and not guaranteed. A definitive answer comes from the motherboard front-panel markings or a quick test rather than relying on wire color alone.

LEDs (HDD LED, power LED) are polarized devices and will only light when the anode and cathode are connected the right way around. Reset and power switches are simple momentary contacts and are not polarized, so their two wires can be swapped with no effect. Most motherboards put a small current limiter on the LED pins, so a reversed LED usually won’t cause damage — it will just not light.

Clear, safe ways to confirm polarity:

  • Inspect the motherboard silk-screen near the front-panel header (labels like F_PANEL, PLED, HDD_LED or small +/- marks). Match the connector to the +/- silk-screen.
  • If the silk-screen or manual is not available, a multimeter in diode mode will show LED forward voltage and polarity.
  • A quick low-risk test is a brief contact with a 3V coin cell: the LED will light when connected with the correct polarity (positive coin side to the LED anode). Keep the contact short and steady to avoid strain on wires or pins.

If an LED still fails after trying both orientations, check the cable and connector for a broken lead, verify the header pins are correct for that function, and consult the motherboard manual for the exact front-panel pinout. This removes guesswork and avoids accidentally shorting the wrong pins.

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Member Avatar for alc6379

I think the white is negative... That's how I did mine, and it works, at least.

Member Avatar for HawkeVIPER

The general rule of thumb for the majority of case manufacturers is:

Colored wires (red/green/blue/tangerine/etc) for positive
Black/White wires for negative =)

--HV

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