Just because it "turned on" doesn't necessarily mean it's working ok. There are several rails on the PSU, the main being 3.3v, 5v and 12v. It may turn on, but one or more of those could be really low. If you have no reason to suspect anything was wrong with it, then I guess it's ok. But if you were having some strange issues you thought may be PS related, then those lines need to be checked. With it powered on it should be checked with a DMM or volt meter. The yellow wire should read 12v, red wire 5v, (both can be tested on the 4-pin Molex connectors), and the 3.3v is the orange wire on the ATX main connector. Of course you also have to have the black lead of the meter touching the black wires on the Molex and black wire on the ATX main connector when you check for 3.3v.
Technically it's considered "ok" if the voltages are +/- 5%. But personally I'd never use a PS that exceeded 3%. Even if the voltages are ok, it still could be the voltages fail when under load. A PS tester can put one under a tiny load, but sometimes not enough. -Clint God Bless Clint Hamilton, Owner http://OrpheusComputing.com ----- Original Message ----- From: Clint: The ATX pin out was just what I needed. Anyhow, when I connected the power supply to an operating motherboard, the power supply did turn on.... which answered the question about it working. Wally On Sat, 21 Oct 2006 02:33:30 -0500 "Support-OrpheusComputing.com" <> writes: > ----------- > The computers with the power supplies that connect > to the motherboard with a single connector can be > shut down by a signal from the motherboard > created by the operating system. I believe that > they can also be turned on by a signal from the > operating system. > -------------- > > That's an ATX power supply. The one's with the two mobo > connectors are "AT" power supplies with an independent > switch. > All you need to switch (turn on/off) an ATX PS is a mobo for > one. You just connect the power connector, then momentarily > short the (usually labeled) "PWR" pins in the mobo front > panel > connector pin-outs. Sometimes it's labeled "power", or > "switch", etc. > > Another way is there are also ATX PS testers for as low as > $10. > It's not good to power up any PS for more than a few seconds > because there's no load on it. A PS tester has a dummy load > it > applies to the PS so it can remain on for a couple of minutes > or so, but no longer than that. > > If this is a one-time thing only and you only want to see if > it > powers up and you have no mobo, then on the main ATX to mobo > power connector you can short a ground (black wire) to the > green (PS-ON) wire. > http://www.orpheuscomputing.com/downloads2/ATX-pinout.rtf > -Clint > > > ----- Original Message ----- > From: <[EMAIL PROTECTED]> > > > The computers with the power supplies that connect > to the motherboard with a single connector can be > shut down by a signal from the motherboard > created by the operating system. I believe that > they can also be turned on by a signal from the > operating system. > > I want to test a power supply independent of the > mother board. What type of signal is required > to turn the power supply on and keep it on? > On what line in the connector is the signal sent? > Some power supplies have a separate two wire > connector that might be used for this purpose. > > Is there somewhere that I can download this > information? Maybe in a PDF file that contains > schematics? > > Wally ============= PCWorks Mailing List ================= Don't see your post? Check our posting guidelines & make sure you've followed proper posting procedures, http://pcworkers.com/rules.htm Contact list owner <[EMAIL PROTECTED]> Unsubscribing and other changes: http://pcworkers.com =====================================================
