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Repairing the ATX power supply unit


If you have some knowledge about electronic component, about multimeter; you can easily learn to repair the ATX PSU. here you find a simple presentation that allow you to understand the role main components with a photos.
Presentation 1:


Presentation 2:



presentation 3:



here you find the schematic diagram:




the component side :




the solder side:


Step 1:



Step 2:


Step 3:



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1 Answer

When I put the plug into the PSU for my sony tower pc the green indicator light just keeps flashing. Now when I unplug the 24 pin connector from the mother board the light on the PSU is steady green. What could the problem be since the computer will not turn on at all?


the PSU has Problem . It is not supplying enough voltage to boot the PC, capacitors inside the PSU are weak or damaged. Its dangerus to open the PSU coz, Capacitors have high voltage currents. If you have the Knowledge of electronics, then open the PSU and detect the Weak or Leeky Capacitors and replace them with new one( this method is for experiment and thrill) . But the replacement new PSU is better , perfect and cheaper then repairing the psu from outside. best of luck

Feb 03, 2011 | Gateway Bestec ATX-300-12EB3 305w Power...

2 Answers

Power supply or motherboard problem?


Hi talissap,

The blinking light is telling you something about the PSU. First check any AC mains voltage select switches for proper setting. US should be 115. Second if you have a multimeter, you could test the PSU for voltage. Disconnect all power to all components. remove all components from the board including cpu, memory . Leave the PSU only plugged into the board. Press power. If the fan turns on then it's not the power supply. The brand power supply isn't the best, I've seen where you need to wait for 5-20 minutes for the blinking to stop, at which time it will fire up. Now, if it doesn't power up, then it's most likely the PSU.

Good Luck,

Mark

Dec 08, 2009 | Bestec (ATX-250-12E) 250-Watt Power Supply

1 Answer

My wife has an eMachines T1600 in her first grade classroom. It worked in June when class ended, but does nothing now when we push the on button. I suspect the Bestec ATX-250-12E power supply, since nothing goes on. Is there a way to test it before getting a new one? I am NOT a computer or electronics expert, although I can follow directions pretty well (installing hard drives, etc.).


Hello there martinsjak.

Here's your GEEK-steer ...

First, I'll presume you have of course "lamp-tested" the wall power outlet, as well as the power strip outlet you using, and that also the power cord is in good repair.

With that out of the way, kudos are in order, because your suspicion of the Power Supply Unit (PSU) is very well founded. It is THE most common PC component to fail. Although it could also be the case power button/switch itself, it's likeliest to be the PSU. But regardless of which, the easiest way to find out is to test the PSU.

You have three options:
  1. Manually test it using a multimeter ... Yuk! Only a guy with a plastic pocket-protector (and thinks it's impressive) would pick this one.
  2. Install the suspect PSU into a KNOWN GOOD working PC. If the PC powers up, you know the PSU works. If not ... well you get the picture.
  3. Test it using a PSU Tester. This is a surprisingly desirable option. Why? Because PSU testers are not very expensive, and if you're like most everyone else in this modern era, you'll be in need of testing more than just this one over the course of time. Check out this very solid choice for a Coolmax PS-224 ATX Power Supply Tester.
Which of the above three is your call. Easy-peasy, yeah?

Good luck to you, and thanks for posting back ...
  • to let me (and others) know how things worked out,
  • if you have any further questions,
  • to provide clarification or feedback.
"Today's the best day of my life ... and NOW you're part of it!"
Via-con-Dios and Godspeed -- Craig

Sep 25, 2009 | Gateway Emachine Bestec ATX-250-12E PS...

3 Answers

i want to start repairing amps. how do i learn?


You will need to enroll into an electronics school to learn how to repair electronics on a component level.

Jun 21, 2009 | Rockford Fosgate Punch 401S Car Audio...

1 Answer

ATX-300GU PSU: 32V around Q4/Q5 circuit


could just be the regulating power transistors are burned out or one of their biosing components, there a few meaty capacitors that may be causing a surge, but the safe thing to do would be to start with a new one, the reason is, modern drives are so sensitive that you could blow their circuitry and then lose the harddisk! All the best - the Yeti

May 17, 2009 | AOpen Power Supply: ATX-300GU (PS4300GU)...

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