Did I fry this PSU????

[Tismedt]

I just did a swap with my wifes system and a new K7S5A rig i built. Basicly I swapped hdd and cdroms, though I also swapped cpu hsf. So I have the amd stock hsf back on, the ddr in and before i put the mobo in the case I hooked up the leds, pwrbtn, rstsw and speaker and optional usb. I had the board laying ontop of the case kind of sideways to test the hookups. plugged in the psu and turned it on. I had forgot to hook the atx connection to the board. When I turned on the power the hsf spun for about 1-2 seconds then nothing. Said oh darn that was wierd I didnt hookup the atx conn. I turned off the power hooked the atx and turned power on hit the button and the psu fan turned for a second and then nothing.

I took the psu out and jumped the atx conn. and the same thing happens fan turns for a second and then nothing. When I had the mobo sitting on the case could I have shorted it out somehow? Ive never done a hookup test like this and I'm not sure what I did

Any thoughts or help would be great.

PS I changed PSU and the mobo seems to be working fine

 

[LutaWicasa]

I'll be interested in any ideas as well. Not the same situation, but have a 400 watt psu that had been fine. Quite a while back, pulled it from a BS case and stowed it away. Took it out today to put into a new case and it does the same thing you mentioned. Get just a very momentary shot of juice and then..............nada

 

[Milkman]

When you say momentary shot of juice is that with the power supply hooked to a motherboard or jumpered by itself?

 

[Tismedt]

Dont know if you were asking me but yes it happens when the psu is in the box and out of the box with a jumper

 

[LutaWicasa]

When you say momentary shot of juice is that with the power supply hooked to a motherboard or jumpered by itself?

Both/either
At first had it all hooked up to a mobo. Fired it up............just a turn or two of fans. Pulled it and jumped, fired it up and......a turn or two of fans.

 

[Robbiem01]

did you set your motherboard directly on metal? You have to at least use stand-offs or put cardboard between it and the case! If you didn't then you prob. fried your mobo. If the fans are spinning it sounds like the psu is working fine but you can test it. Just take a psu you know works and hook it up with your system. If same thing happens agian then its your mobo not the psu. I hope this helps.

 

[YMAN]

Have you all made sure that the voltage switch in the back, is
set to the proper voltage? (If you have one)

If you are in the US and it is set to 220, some supplies will
do nothing, others will run at 1/2 the normal voltage.
In some cases something like what you have will happen.

 

[LutaWicasa]

Nope, mobo was/is properly mounted in the case. Yes, switch to select 115/220 was about the first thing I checked.

 

[Tismedt]

did you set your motherboard directly on metal? You have to at least use stand-offs or put cardboard between it and the case! If you didn't then you prob. fried your mobo. If the fans are spinning it sounds like the psu is working fine but you can test it. Just take a psu you know works and hook it up with your system. If same thing happens agian then its your mobo not the psu. I hope this helps.

In my case yes the mobo was set directly on the metal of the case. And as stated in the original post I switched psu and the mobo is fine. You say if the fan turns at all the psu is good. Can you explain this a bit more?

Thanks

 

[YMAN]

Have you tried to start the power supply with nothing on it
but the internal fan(s)?

If you have not remove all plugs and instert a unwinded
paperclip in the hole with the green wire attached, and
the other end of the paper clip to a black ground. You
may also use a Power Supply Jumper. Then plug it in to
a power source and what happens...

Also I would try to remove all the plugs and reseat them.


--------------

I will say I have done some work in the case a few times
and, the blasted thing would not start or it would jurk the
fans. I replaced the supplies and what do I find... sometimes
they will work a few hours later! It happens every 1 out of 2
times or so.

 

[YMAN]

You say if the fan turns at all the psu is good.

This is not always true.

One thing I will say however is this is often caused
from a short, or faulty components such as a diode,
capacitor and such.

If it shuts down immediatly; but runs for a half a second
to a few seconds. This may be the case. This is why
in my post above I stated to reseat all the PS cables.

 

[Robbiem01]

yman seems to know much more then i do. I am speaking for experience of frying a motherboard but he actually knows how all the stuff works. Just ignore my other post if anything conflicts with what yman says.

 

[Tismedt]

I have tried to jumper the psu and the fan turns for a second or maybe two then looses power. From what you have said it may be a diode got damaged when i fired the thing up with it sitting ontop of the metal case. Though at the time I only had the case leds, power btn and speaker hooked to the mobo. Is the psu grounded to the case by default?

 

[YMAN]

The PS does ground the case by means of a green wire
connected to a metal area of the PS. Thus when a PS
touches the case it is grounding the case, diverting power
to the 3rd outlet pin (round one) otherwise known as the
ground.

If you want to see if your case is properly grounded, take
a case fan and take the black wire (-) and firmly hold it to
a metal part of the case. Leave the red/yellow (+) wire properly
pluged into the molex. If the fan spins, you have good
grounding.

If you have another power supply, I would definatly test
it out on the motherboard.

However placing the motherboard or any other component
on a bare metalic surface will cause the soldier points to
touch the metal, thus shorting everything out. This may have
caused some type of short, damaging the power supply's
internal components such as the rectifier diode, witch keeps
power moving in one direction. If power suddenly moved
backwards or irregular way it could cause the safty devices
in the power supply to shut off one of the rails or all the rails.
Witch is the senario that you are having.

I am not saying for fact that an internal component has
been damaged; but taking into consideration that that
power supply does do the same thing in a jumpered setup,
makes me confident. I ask you to try the board with another
power supply to see if the motherboard is also damaged as
you may have caused a mass shot.

 

[Tismedt]

Luckily I did not do any damage to the mobo. It is working fine in my wifes system. She is listening to spinner.com right now.

Is there any quick easy fix for this as I believe that the diode you mentioned is prob the quilty part? Or maybe I should RMA the psu as I just got it (or one just like it) from newegg last week hhhmmmmmmm.

 

[YMAN]

If you can RMA it I would do that over locating the
defective part. That is a complex job witch also
needs special testing intruments.

 

[Tismedt]

Thanks YMAN for your help. I will rma the psu tomorrow as now it is bed time for me. Thanks Again

 

[YMAN]

Glad I could help!

 

[LiGhTBoY]

Did you guys forgot that PSUs have built in safety systems?
Here's what you can do to fix your PSU:
First UNPLUG (it's in capitals because it is importand ) the power cord and leave it for a few mins to "calm down".
Then take a light bulb and connect it to the live and neutral power pins (CAREFULL THOSE THAT ARE IN THE PSU CORD NOT THE PLUG ) and wait a couple of seconds.
Connect everything back as normal and fire up.
It should work just fine after this.

PS
You connect the light bulb to draw the current in the capacitors and thus emptying the PSU.

 

[Tismedt]

Thanks for the input lightboy but I have allready sent it back for rma. If the need comes p again I will remember this option.