Possible PSU Issue

jpkang

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Hi,

this is my first post, I ran out of other places to find support. Basically I have had my computer build for less than a year. I recently had to clean my house and move my desktop from the top of the desk it was on to the bottom. So I basically turned it off (may have forgotten to turn the switch off) and moved it to the floor. I have carpeted floor but my desktop is on top of rubber stoppers. I connected everything back to my computer and did not bother to turn it on because I have a razer mouse connected to it and it glows when the power is going through the desktop. Left for school came back and my computer will not turn on anymore. I am not sure what the issue is, I may have moved it a few times over the carpet trying to adjust it under the desk, but it was "working" before I left it alone. No one else touched it that day and now I can not get any sign that power is going through.

Is it possible that over the course of the day the PSU built up a static charge and is now "burnt out" (even though it does not look like it) or possibly my MOBO (which also does not look burnt out)? I have no spare parts unfortunately but I wanted to know if anyone knows what could have caused it and if there are any temporary fixes. My PSU is a 500W PC Power & Cooling Silencer MK III. I have had some power issues in the past but it was just some cabling issue, this time I checked all cables and even disconnected everything and put it back together and still nothing. I am going to try to acquire a spare PSU to see if that makes any difference but I really hope I don't need to buy more parts. Please help.

Thanks.
 

jpkang

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So it affects the PSU even when the computer is off? I thought it may be a temperature thing, but uhh yeah that was not it. Man I really need to get spare PSU then.
 

No it doesn't affect the PSU turned off.

Have you checked that the PSU switch is on the "I"... my guess is you may have switched it off accidentally. If this not the case but the PSU fan doesn't run with the computer power switched on, then the PSU is dead.

You could test the PSU disconnecting every power connection to motherboard and drives, the psu switched off from the I|O switch on the rear, use a paper clip bended in a "U" shape and insert it on the large 24 pin PSU connector... insert one end of the wire in the green wire pinout and the other end to any black wire pinout. Next switch the PSU switch to on (I), and the PSU fan should run.. if nothing, replace the PSU.



Some info on how to test a PSU:

How to Check the Power Supply With a Multimeter | eHow.com
http://www.ehow.com/how_4896858_check-power-supply-multimeter.html#ixzz2Kx2RXY7X

testing power supply connectors with multimeter
http://www.youtube.com/watch?v=EpmsYrDRcG0

24 pin connector voltages
http://www.smps.us/atx-connector-20-24pin.jpeg
 

jpkang

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So just to be clear, as I have never done that before. I just disconnect my PSU from everything and then place the paper clip in the outlined pins and then plug my PSU and switch it on to see if the fan goes? That sounds so simple, I hope it works. But wait if it does work then its definitely not my PSU is it...

...Ok so I tried it out and my fan does turn on...so it is not a PSU issue then right? -_- now I don't know what I should check next, I am guessing the MOBO...
 

That is only part of the test.. it proves the PSU works but according to symptoms it works only partially. As it works partially, at least the mobo led should glow, and if it didn't, the connections may have been lose... so reconnect the PSU to the motherboard and drives and make sure the 24 pin connector is firmly attached, and see if now the computer fans and drives run.. if they do but there's no image, give it time... i've noticed cold weather affects how long before you get image on the screen even with a new PSU, and with a weak PSU it may take longer... so if all fans and HD work, give it at least 10-15 minutes before shutting the PC down.

Sometimes the motherboard or GPU cause a blank display so you have to give the system time to warmup and discard weather is a factor. If after 15 minutes there's still no image, you next need to test the PSU for voltages according to the links provided previously. This has to be done to know for sure it's the PSU and not the motherboard or GPU... but I'm guessing it must be something simple and minor because moving the computer could only cause lose connections to act up and not cause damage to either mobo, GPU or PSU.
 

jpkang

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Do all MOBOs have an LED light and/or sound. I feel like mine does not have any. I see no light or hear anything. My MOBO is a GIGABYTE GA-Z77M-D3H-MVP. In my manual it does not say anything about diagnostic lights or sounds, so I am not sure if anything is really happening.
 

jpkang

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Ok, so I finally was able to obtain a Multimeter (not a digital one) and for the most part all my readings are correct except that all the pins that have 3.3V, my reading shows 3.2V. Is that not sufficient enough? Also I found my MOBO light it turned on when I unplug the power to the MOBO plug to eagerly.

So if it is 3.2V does that mean I have to get a new PSU?
 
The 0.1 volt difference may be due to the meter being analog... in any case it should still power what ever needs 3.3V. The MOBO LED doesn't sound normal... you unplug which connector from the mobo? the 24 pin connector or the processor connector?. The LED normally lights up when you give the motherboard power, not when you take it away. Infact the LED should stay lit when the computer has shutdown and gradually die down secods later.
 

jpkang

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I mistakenly unplugged the 24 pin connector and the LED (Diagnostic) light flashed yellow and turned off. Every time I test my MOBO, the computer does not turn on and there is no LED light that is on. I tested if my drives turn on apart from the MOBO and they work. But no signs that the MOBO is working. I also tested to see if my RAM would affect boot up, so tested each of the slots and still nothing new.
 
OK, now that sounds about normal or LEDs. But to be honest I don't know how accurate testing the PSU with a voltmeter is... As example: I have a spare PSU that didn't work the last time I hooked it up.. It tests at the right voltages, but it doesn't make any computer work... everything apparently turns on, the LEDs, the fans, drives, everything seems to turn on/run, except that it doesn't give display and the BIOS doesn't beep... So I guess a test with a voltmeter is not as accurate as we've been led to think... I know that voltage is one thing but amperage is equally important.. for example car batteries, they can be dying and as you trickle charge them they may read 12 volts but they may not deliver enough amps to even work the starter. So, in the same tone of logic, the computer PSU may deliver the right voltages but not at the right amps. The PSU should supply I believe around 15 amps, but no one talks about that, and it should be as equally important to test.. and I think a PSU tester (+/-$20) may be what you need to make sure which; the PSU or motherboard is the problem.
 


Well, the tester would be the cheapest way to detect the damaged part. A new PSU, or motherboard are alot more expensive and a repair shop would probably be double than a PSU or mobo, so the cheapest posible solution is a PSU tester so you know exactly which; PSU or Moterboard you need to replace.

You could borrow a PSU if possible, or test your PSU on another computer.. and that would be $0.00 to diagnose the problem... other than that, you could disassemble the computer and breadboard it and try it... and if nothing, put it toghether again while cheking for lose objects... it's possible a foreing metal object was trapped somewhere since the computer was built, and moved to a vulnerable place when you moved the computer.

In my experience motherboard dont just suddenly die, they start giving different symptoms and so do PSUs, so if the problem was not preceeded by previous problems it may be something as simple as checking for foreign objects, cleaning slots and pins and doublechecking all digital and power connections and switches.