Handy power supply tester

[everell]

This is a handy ATX power supply tester. First remove a 20 pin power supply connector from a "no good" motherboard. Then wire switch and LEDs (with resistors) to the connector pins as numbered. Photos show tester connected to ATX power supply, plugged into wall socket, with switch in OFF state, 5vsb LED should light up. Then tester with switch in ON state. All LEDs should light up. Then one photo showing LEDs glowing in dark. Simple to build, and very inexpensive!

[everell]

Re: Handy power supply tester

I was surprised at the lack of interest in this handy ATX power supply tester. It is one of my most important tools. Why? It gives you a visual indication as to whats going on.

With power switch OFF, plug power supply in. The 5vsb LED should light up immediately. If not, that is where to begin troubleshooting. The 5vsb must work or nothing else will work.

Next, turn the switch on, and the remaining LEDs should come on. If not, it gives you a clue as to where to begin. If only one LED is not ON, then that is the bad circuit to be fixed. If the LEDs come on momentarily, but then go off, it means that the main switchers are working but something is loading the power supply improperly and the protection circuits are shutting things down. If the LEDs do not come on at all, the problem is most likely with the main switching transistors circuitry.

Why is this so handy? You can look at the LEDs and quickly tell what is happening much faster than you can measure each circuit with a voltmeter.

[370forlife]

Re: Handy power supply tester

Too many cheap pre built ones out there.

I actually have an ultra one that has LED's for all voltages including minor rails like 5vsb, -5v, -12v. It checks to make sure they are inspec.

http://www.tigerdirect.com/applicati...108&CatId=1107

[momaka]

Re: Handy power supply tester

I was surprised at the lack of interest in this handy ATX power supply tester.

Never really saw this thread (perhaps I wasn't here that day or something).
It would be nice to have one, though. I have some junk LEDs, might as well put them to good use. Just need to find me a motherboard connector or a dead motherboard.

[sofTest]

Re: Handy power supply tester

If you got the parts for "free", your tester is nice, everell. Otherwise I agree with 370forlife. I got myself this tester from DealExtreme. I've only used it once, but it did the job confirming my suspicion.

[stj]

Re: Handy power supply tester

you need to make a load with led's - lamp-bulbs for example.

[berniedd]

Re: Handy power supply tester

Well, your tester is fine for detecting no-output conditions, but the real test is measuring the voltages with a real voltmeter when the PSU is loaded. I don't rely on the motherboard's voltage readings from the BIOS menus. Some of them are not accurate.

[everell]

Re: Handy power supply tester

So right you are. I use this tester for troubleshooting bad power supplies - like really bad. I test in no load condition first - just to see what I am up against. Once I see some LEDs working correctly I start putting a load on the power supply. I usually use HDD and CDROM.

Some power supplies require a load for proper startup - most don't. On all ATX power supplies that I have worked on, the 5vsb LED either came on instantly - or that was the starting point for repair. It is a very quick visual test. If LED is too bright, confirm voltage on 5vsb with voltmeter. If too high, you haven't hurt the LED, but you haven't blown a mother board.

[i4004]

Re: Handy power supply tester

>I was surprised at the lack of interest in this handy ATX power supply tester.

not many deal with as many psus as you, and when they do, they can use meter(s)...

but it's a good thing, and i give you thumbs-up!
those that work with psus a lot should have something like this.