LED always on mod ??

[Rover3500]

Hi all,

I am going to be rebuilding my comp this week having bought new hardware, I thought I would redesign my case at the same time.

One thing I was looking at doing was to fit UV feet to my mountain mods case and to light them using 5mm UV LEDs.

What I was wondering is if there is a way to power them via the PSU so that they are on constantly, even when the comp is off.

They would use a very small amount of power but I'm not sure if the mobo switching cable from the PSU would work without damage to the PSU.

Has anyone tried this or is there another solution ?

Another problem I have is with the PSU, it is a 1000w Enermax Galaxy and when I go into a game it starts to whine in a high pitched way, it is not very loud but still anoying, my graphics are ATI 3870X2 and a have 2 fitted, I know they pull a lot of power but the PSU should cope. I have tried dissconnecting different cables and find that if the 8 pins are connected it will whine without the 8 pins it's ok.

Thanks in advance for any help.

[Jim]

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.

[Rover3500]

Originally Posted by name='Jim'

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 ?

[MeltedDuron]

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!

[Jim]

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.

[Rover3500]

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 ?

[Rover3500]

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

[Rover3500]

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.

[Jim]

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

[Rover3500]

Originally Posted by name='Jim'

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.