BleepingComputer.com: How To Test A Power Supply

Update:

I got the power supply yesterday and installed it as soon as I got back from picking it up at the post office. I felt like a kid on Christmas morning!

Anyway, that's what it was! I tested it, putting the jumper on to see if the fan worked, before I installed it.

It's a "new" computer that someone gave me after it sat in their garage for a year and a half. It's running Windows ME and isn't too shabby for a back up.

However, after tinkering with it for awhile, cleaning up all the crappy crap that was on it and updating through Windows Update, I seem to have lost the ability to access the internet. Neither Firefox or Internet Explorer can access the internet. I will post this under a "new issue" within Windows 95/ 98/ ME.

Thanks to all who helped!

This post has been edited by elomont: 13 February 2009 - 10:21 PM

hope its ok to jump on this thread

ive been given a pc (sh*t heap) with what i think is a dead 400w psu. The connector is a 20 pin and wire 14 is grey not green. Is this the wire i need to put the jumper to please? there are no green wires at all in the motherboard connector.

thanks guys.

mazroy, on Feb 17 2009, 07:39 AM, said:

You really should start your own topic, fortunately this topic had come to an end so your post is going to disrupt it. Another reason that you should start your own topic is because with the number of posts in this one most people will assume that it has been addressed and is being taken care of and will not read it.

To answer your question, it should be the green wire if it is a ATX PSU. Some Dell PSUs are non ATX and have a different pin configuration, so if your computer is a Dell you will need to determine this.

mazroy, on Feb 17 2009, 07:39 AM, said:

Pin 14 should be green, however, if it isn't, go ahead and short it to ground to test the power supply.

http://www.formfactors.org/developer%5Cspe...X12V_PS_1_1.pdf

dc3, on Feb 17 2009, 01:19 PM, said:

apologies for that dc3 and will make sure it doesnt happen again. on looking closer at the psu label it does actually say Gray = ps on. ive shorted it and no responce so looks deffo like a new psu needed. Thanks for the info dc3.

DaffyKantReed, on Feb 17 2009, 01:44 PM, said:

thanks for the info daffy.

There should be a green wire in the 20/4 pin connector, this is the PS_ON. If you have the 20 connector upside down when you count the pins the gray wire will be in pin 14, turn it over and count again and you will see that it is the green wire. There is only one green wire in the connector, so it doesn't matter what pin it is in.

The gray wire is the PWR_OK, Power Ok is a status signal generated by the power supply to notify the computer that the DC operating voltages are within the ranges required for proper computer operation (+5 VDC when power is Ok). Shorting this to ground will not turn on the PSU.

This post has been edited by dc3: 17 February 2009 - 10:23 AM

took a couple of snaps just to show no Green wire

Seeing is believing, I have to admit that this is the first time that I've seen a gray wire used for the PWR_ON before. I tried googling that model and didn't find anything, what is the make and model that it came out of?

ive no idea dc3 theres nothing to give me a clue what make or model it is, looks like it could be a self build job. going to chuck another psu in it later.

found this on wiki dc3.

The motherboard controls the power supply through pin #14 of the 20 pin connector or #16 of the 24 pin connector on the motherboard. This pin (Usually the green wire but can be the grey wire Dependant on PSU manufacturer) carries 5V when the power supply is in standby. It can be grounded (connected to any black pins) to turn the power supply on without having to turn on the rest of the components. This is great for testing if you don't have a spare motherboard around, or don't want to connect a suspicious power supply to a working motherboard with risk of damaging it.

http://en.wikipedia.org/wiki/Computer_power_supply

all sorted now, put working psu in and its fine.

thanks for your help guys.