Tut: How To Start A PSU By Itself

[killermodz]

TUTORIAL- HOW TO JUMP A PSU

::EDIT:: I am reposting this tutorial from the case mods section to here because it think it will do alot more good here now, ::EDIT::

1st thing is first. Unless you plan on having a load full time on a jumped psu, only jump it for a short period ( 2-3 seconds max) at a time. Running a psu with no load can cause it to damage itself. Also please disconnect the psu before jumping it, and after finished.

Toolds needed.

1- ATX PSU
2- Wire Strippers (or teeth, depending on lazyness)
3- Short length of wire (or 2 if you do the optional step)

Its a 1 step process! Grab your psu, examine the atx connector itself, u'll notice a green wire with a black wire on either end of it. Take your length of wire, and use the wire strippers (or teeth) to strip a small section of cover off each end of the wire. Insert one bare end of this wire into the opening of the green lead on the atx connector, and the other end into any of the 2 black lead openings beside the green lead opening. This will jump the psu, and if it is plugged in (i suggest jumping first, then plugging it in), the psu will turn on (that is if its any good). Remember only run an unloaded psu for 2-3 seconds MAX!


Notice the jump from the black and green wires.


Following these directions will gve you a sucessful psu jump.

Killa200

[aszyd]

What will happen if you run it without a load for very long? Will it blow up or something?

[Gh3tt0PC]

I think some of the capacitors and transformers are made to run under constant load so they will short out or something...I did it on one of mine a while ago and it started making high pitched noises....they kept getting louder and I didn't want to kill it so I turned it off....its fine but i think it woulda blown if left any longer...

[aszyd]

Ahh, never knew that.

[killermodz]

almost all the components in a psu are meant to have a load on them. Without one they are converting all that un-used wattage to heat, and backed up charge in the caps, hence the high pitched noice

[Nerd101]

i know you can get a [ Y ] connector dont know what it´s called but it allows you to run dual psu. like then one you can get when you need more molex connector´s

[SteveR]

Nothing bad will happen if no load is present. According to the ATX12V Power Supply Design Guide, a properly designed PSU will be able to run for an indefinite period of time without a load, with no harm done. The only caveat is that some power supplies may trip into a shutdown state without a load present, but I haven't come across any. That being said, its still a good idea to load, at a minimum, the +5V line, so that the load draws around 1 amp or so. This primarily helps to stabilize the voltages. I built a tester/breakout that plugs onto the ATX connector, has a switch to turn it on and off, lets me connect to the +12, +5, -5 and -12 volt lines, and uses a pair of power resistors to load the +5v line. Every PSU I've used it on has been happy (though I haven't always been, those resistors get REALLY hot after about 5 minutes ).

[Tim]

I new that one, lol, nice tough

[AMDGUY]

Killer, I know you had that on here somewhere before, I thought it was a sticky?!?
Glad you reposted it.

[killermodz]

SteveR, that is also an ATX12V standard. Before the update and use of that stand, regular ATX psu's were not required to maintain functionality without load.

[SteveR]

True true, but even some old AT power supplies I've had kicking around (some from early 90's, some from late 80's, and some that are like boat anchors, mostly before there was any real standard) have all run fine without a load. Though I will admit it is best to put some sort of load on it. The adapter I built uses a pair of 10 ohm power resistors from Radio Shack in parallel on the 5 volt line, and thats plenty.

[killermodz]

yeah, ive had some good and bad exp. with AT psu's and no load.

You should make a tut on your load adaptor, could be really useful,

[devilgoob]

Yeah just put some type of load on it. My dell powersupply doesnt work unless it has a load on it Dell powersupply's suck especially the pin layout

[BubbaFrag]

Originally Posted by SteveR

Nothing bad will happen if no load is present. According to the ATX12V Power Supply Design Guide, a properly designed PSU will be able to run for an indefinite period of time without a load, with no harm done. The only caveat is that some power supplies may trip into a shutdown state without a load present, but I haven't come across any.

heh heh, i think i've got one of those - i jump the green to black wire, plug 'er in and it shuts down almost immediately.

is it only the +5V supply that needs to be loaded? would it be beneficial to load all the supplies to the same degree?

thx,
Bubba.

[dannylill1981]

nice one i can finally ditch the crappy 250 watt at psu im using to power my fans and replace it with a better 350w atx i have lting around that is musc quiter and doesnt have that dopey switch attaced to it. instead of putting wire across the pins can you fit a really neat switch instead??

[4-n-zics]

Originally Posted by dannylill1981

nice one i can finally ditch the crappy 250 watt at psu im using to power my fans and replace it with a better 350w atx i have lting around that is musc quiter and doesnt have that dopey switch attaced to it. instead of putting wire across the pins can you fit a really neat switch instead??

yes.. or you can set them up to power on together with the computer power switch:

switch:

http://www.virtual-hideout.net/guide...mods/print.htm

switch box:

http://home.earthlink.net/~bombtek/website/Swithbox.htm

2 PSUs together:

http://www.pc-mod.com/articles/atx/atx5.jpg

AT and ATX PSUs

http://www.kmcsonline.com/casemod/dual_psu/

[dannylill1981]

cheers 4-n-zics much appreciated.

[Nookie420]

you can also short pins 4 and 6 on the top row. its how koolance does it to fill the h20 system.

[killermodz]

Nookie, jumping pins 4 and 6 on an atx connector would connect 2 grounds, not the psu on and a ground, because psu on is on pin #8.

Bubba, its usually an either or situation. You either load the 5v or the 12v. Its safe practice to do both though because some psu's have the 12v and 5v rails on seperate circuit runs.

[4-n-zics]

Originally Posted by killermodz

Nookie, jumping pins 4 and 6 on an atx connector would connect 2 grounds, not the psu on and a ground, because psu on is on pin #8.

Bubba, its usually an either or situation. You either load the 5v or the 12v. Its safe practice to do both though because some psu's have the 12v and 5v rails on seperate circuit runs.

It is Pins 4 and 6. The green wire is Pin 4 and one of the grounds is Pin 6.