salvaged computer power supply

You spent more effort typing your post than typing "computer power supply pinout" into google...

Dave spake thus:

Well, I also would like to know what the OP asked about, in order to use these abudantly-available power supplies for other applications. Instead of a snotty reply, you could have answered the question if you knew, or simply not posted anything if you didn't.

1. Google for colour codes.
2. Switch power supplies do need a minimum load for operating.

No.

This question is asked all the time. At the very least, people could search "google groups" to find the answer from a previous time someone asked the question.

But there are likely websites about it too.

Take note that this is a repair newsgroup, and the poster is claiming the power supply is working. Hence it's not even relevant to this newsgroup.

On the other hand, the "FAQ" for this newsgroup, more a set of short books on the repair of various pieces of electronic equiment, is at

I can barely recall the original post, but to me it wasn't clear if he was actually looking for how to do it, or had done something that he thought was the right path and it didn't work. Properly phrased questions often get better answers.

Someone who can be direct, "I looked up the pinout of the ATX supplies and when I did this to it it didn't turn on" is actually far more informative than the original post. Because then repliers can say "did you load down the supply?" or "Are you sure it's got standard pinout?" or "how do you know the power supply is working to start with".

Michael

Never trust color codes because A) you can't be sure a company follows them B) even if they did, you can't be sure that one specific power supply was wired with the wrong colored wire. (Not likely for a mass-produced item, but not unheard of.)

Either the pinout on the connector is standard, in which case they can look it up, or it's a proprietary pinout and one has to find the exact pinout used by the specific manufacturer. But in either case, the pinout is a far better method of figuring out which wire is which than color coding.

Michael

Michael Black spake thus:

You know, I looked in there; I don't want to be obtuse, but I must say it was less than helpful. I mean, I have no doubt there's a ton of information there, probably including answers to the very questions the OP and I have, but it's just too damned hard to find them, to sift through all that stuff. The search function simply looks for text strings in the articles. Isn't there some kind of table of contents or index to this thing? Unhelpfully, it's divided into files with cryptic names like "monnew.htm" and "odnew.htm".

David Nebenzahl spake thus:

Well, I did find the TOC, but even then I'm having difficulty finding stuff relevant to using SMPSs for unintended purposes.

Can you post a link to (or location of) some references to this in that database?

There are two versions of the newer ATX power supply:

In either case, there should be some load (disk drive, lamp, power resistor) across at least one of the outputs for the supply to be able to regulate properly.

John

Most PC power supply's require a load before they will start, motherboard, floppy drive or an automotive 12 volt bulb connected between 12v and ground might work. If it is an AT power supply with the power on off switch all you should need is the load. If it is an ATX power supply without the on off switch Gogle for the pin out, there is a wire that you momentarily short to ground or another wire....

OTOH, sometimes on AT supplies, the cooling fan is all the load that's necessary.

jak

I found it by a process of elimination, snipping wires in a certain order until I had it narrowed down to a couple of candidates. Then I made my best guess, grounded the green wire, and now I have a working power supply.

Hi!

Why is this mentioned when the topic of computer power supplies comes up?

Over an eleven year span I've found only *one* computer power supply that would not work properly with no load.

William

Sam Goldwasser has an FAQ for this topic. It can be found here (the FAQ was just updated a few days ago).

A couple things to remember:

Switch mode power supplies -- that are used in modern computer to generate high current - have high voltages (> 250 volts DC inside).

Many electronics technicians have no bench experience with high voltage (one hand in your pocket). IF you have little electronics repair / service experience -- it is always best to initially perform such work under supervision or mentoring. Sadly, many of the technical and community colleges that have offered course work in this area for over 50 years -- have discontinued their programs (lack of students - although the interest or curiosity among the public appears to be same).

gb

Additional web site (and there are several on this subject)

Cheap garage workbench

DIY

So, what you're saying that not only are you ignorant, but you are too lazy to rectify that situation as well.

As suggested in my original post, I took the liberty of performing the google search for you. 705,000 relevant pages. 10 on the first page that would answer your questions. Go find them.

People in this newsgroup are more than willing to give a lot of effort to help you, but you've got to demonstrate that you've put even the teensiest bit of effort into solving something yourself, or at least having thought about how one might solve it, to get a helpful response. Electronic types tend to be on the sarcastic side.

Has it ever occured to you that if you're not smart enough to source this information yourself, you really shouldn't be playing with electricity?

Dave spake thus:

So now you're adding insults? That'll get you far, I'll wager.

No thanks to you, someone near the bottom of the thread gave a link to a site that shows exactly how to do this:

Check out this site