Power LED mod
 

Hi all,

I would really appreciate your help in this matter if you can, as I looked in a lot of areas for many hours and couldn't find the right information.

I need to build a small circuit board having a bi-color LED to indicate a power ON state (Green or whatever) and S3 standby state (amber or whatever). And need the LED to turn off when computer in OFF state.

I have established that I need to use the 5vsb (brown wire - pin 9 from the atx power supply) but this will lit the LED even when computer is in OFF state.

So, later I found that I need to use a NAND gate to achieve the desired results. But I have no idea what a NAND gate is, neither what wires I need to use.

Thanks again for looking into this.
Riado

Re: Power LED mod
 

It is very siomple in itself. You just need a bi-color LED, preferably a 3-pin LED, RED/GREEN, and two small cables with the ends having flat plus that fit over the PC's front panel indicators. Try with 330 ohms, but if they are too dim, you do not need them. The output of the front panel connectors has current limiting built-in, so the bi-color LED can be connect directly without current litiming resistors. See my diagram below here.

Attachment 5925

The bi-color LED can be purchased at Radio Shack, or online here...
http://www.allelectronics.com/make-a...-3-LEAD/1.html

If you use 2-pin bi-color LED, you will need more complicate driving circuit.

Hope this help.