need a solution for my LED

[trdsw20]

I changed both of the power and the harddrive activity light on my box recently. The only problem with is that the power light doesnt shine as bright as its supposed to. I measured the voltage that comes out of those two leads and it came out to about 2.74V. The LED that I am currently using is a white radioshack led measured at 3.6V 20mA. Is there a way to safewly increase voltage (caps, i took a begginers electronic course but thahts all it was) or is there another solution. thanks
Oh yeah the harddrive activity led came out ok

[KILLorBE]

The safest way is to use an optocoupler like the 4N25, there are other ways (as always) but I recommend this option, as it's safe and cheap......Maybe not the cheapest but why take a risk? it's only ~$1 (Incl. 470 Ohm resistor).

Let me know if you need a schematic, I'll draw one. **EDIT** No I don't need one, KILLorBE made one:p :rolleyes:

[KILLorBE]

Made a scheme, if you use 12V the resistor (R1) should be 470 Ohm, if you use 5V the resistor (R1) should be 82 Ohm.

It should work, if you're not to sure I'll build one myself and give it a try, but it's pretty hard to screw up your MOBO this way.

Let me know if you have any questions.

**EDIT** The 4N25 can take upto 260°C for 10 seconds, so your soldering skills doesn't have to be great (That is soldering the leads, so don't try to heat up the chip to 260°C for 10 seconds:D ).

[trdsw20]

Actually its not coming off either the 12v or the 5v. I dont have the luxury or choice of choosing one of those lines. The line I am talking about comes straight off the mobo (you know the front bezel lights).
Are you suggesting that I use a 12v line to do it?

[KILLorBE]

You should connect the wires that come from your MOBO (HDD or Power LED) to pins 1 and 2 on the 4N25 (Black or white is usually '-', and the colored wire is usually '+'...uhh if you got the connector plugged in right :p ).
Connect a black wire from a molex connector to pin 4 on the 4N25, connect the slightly shorter lead of the LED to pin 5 on the 4N25, a resistor on the other lead of the LED, and connect that to the red (5V) or yellow (12V) wire on a molex connector.

Personally I would use 5V (Less dissipation).

BTW: If you can't find a 4N25 you can also use a TIL111 (Same as 4N25) or a TIL113 (same connections but better specs --> can handle more mA).

[Element-Xero]

same thing happened to me with my Epox 8k7a. All I did was grab a line of 5v off a molex and put a resistor inline with the blue LED. When you're computer goes on, the power supply goes on, so its the same effect as being plugged into the mobo.

[KILLorBE]

OUCH what was I thinking:eh?:

Just do what Element-Xero suggested, easy and cheap.