You could run the LED's off the 5vSB rail on the PSU which would have to be taken from the main ATX cable. The 5vSB rail delivers a +5v standby voltage to certain components on the motherboard such as USB devices (so they can power the PC on).

Most 5vSB rails are around 3A, so just be sure not to put too much load on it.

You could run the LED's off the 5vSB rail on the PSU which would have to be taken from the main ATX cable. The 5vSB rail delivers a +5v standby voltage to certain components on the motherboard such as USB devices (so they can power the PC on).

Most 5vSB rails are around 3A, so just be sure not to put too much load on it.

Do you know what pin number that would be on a 24pin mobo plug to save me testing them all ?

Edit: hahah jim-bob beat me too it... I think my modding a USB header with wake on USB enabled is probably the easiest way....

Edit again: +5VSB should be on pin 9 of the ATX connector...

If you have a look at your PSU specs, you may be in luck. It'd take a bit of work and you'd probably have to splice the ATX cable but you can tap into the +5vsb rail which provides power to the system even when it's not running for things like wake on lan and wake on usb.

If you can't manage that or don't want to mod anything then the only other ways i could see this happening are either using batteries, using USB via a spare mobo header, find the +5v pins and do a bit of creative wiring. It should work if you turn on wake on usb in the BIOS, but watch out for the current draw of the LED's.


As for the PSU whining, I've heard thats pretty normal these days :( you could try tapping firmly on the side of the PSU a couple of times to see if it goes away, usually it's caused by an inductor or other component vibrating but I wouldn't get your hopes up, the rest of your rig is pretty immense too and you're probably running that Enermax close to capacity.

Good luck with this, if you do decide to do the LED mod please post pics!

My preferred method would be to grab one of these:

http://www.ebuyer.com/product/141082

The 5vSB rail is normally on a purple wire (Pin 9). If you splice one of the above at least it will give you the option to remove it from your rig at a later date without voiding the warranty on your PSU.

Thanks for all the advise, using the 5v rail sounds a good option, I'm just waiting for the feet to come from the USA being as you can't get mountain mods in the UK anymore, then I will be building the new system.

Does anyone know what wattage a 5mm UV LED would use as an average, I can't see it being very much ?

Hmm just had a thought, the LED's I have here are standard for a computer so I would guess that they are 12v, will I need to buy new LED's for 5v or build my own using resisters for 5v

Or will standard computer case LED's work with 5v ?
Thanks again

I think I just answered my own question
I have just checked the molex on the leds and they run to the red wire side of the connecter from the PSU (Molex), which I think is the 5v (yellow is 12v if I remember correctly ?)
Can someone confirm this,
Thanks in advance.

Yeah red wire is 5v. Most common LED's are either 3v or 5v, so it looks liek you're in luck :)

Yeah red wire is 5v. Most common LED's are either 3v or 5v, so it looks liek you're in luck :)

Thanks for the confirmation, my multimeter is broken so couldn't test myself.

Should look nice to have the odd UV showing even when comp' is off, easier to find in the dark, lol.
:yumyum::yumyum::yumyum:

Thanks all for the help,
After some testing my 5v leds that I want as always on total 0.37 amps so well within the 2.5 amp supply.
I modded my psu cable with a molex across the purple 5v wire and a black neg'
Now it works a treat, at least the light do, having problems with my new mobo now, constant reboot loop every 3 seconds (nothing to do with the led mod):nono::nono:
Looks like an RMA on the mobo or cpu (gigabyte X58 Extreme - i7 920 DO Stepping):mad::mad::mad:

BTW I bought a new PSU as I just hated the whine from my Enermax galaxy 1000w
Got the Enermax Revolution 85+ 1250w (wow so quiet):worship::worship: