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DELTA ATX 500Watt Power Supply Repaired

By on June 25, 2015
atx 500watt repairings










A friend of mine gave me this DELTA POWER SMPS 500 watts, but he told me it was working fine and one day it stopped working. He had already bought a new one for his PC.

atx 500watt repair

I really liked one detail of this device; it has two fans: one in the bottom and other in the rear; this means a better cooling.

Of course it was opened, only four screws in the upper case.

atx 500watt repairs

As you can see in the photo above, it was asking for a Preventive Maintenance, but first of all it had to be repaired.First thing I saw was one of the big filter capacitors (470µF/200 volts) was bulged. Notice in the photo below it is inflated for both sides: up and down.

atx 500watt repairing

It was de-soldered from the PCB and I wished to see with my Blue ESR Meter the ESR’s value to experiment and it was a little high. The other one was checked as good.

atx 500wattrepair

But I had a situation here; I had not any capacitor of 470µF/200 volts to substitute the bad one. So I had to take a pair of 560µF/200 volts then, of course they were tested with the Blue ESR Meter too, the values were 0.4 and 0.6 and it means these e-caps were in good conditions.


The rest of the e-caps in the PCB were checked and all of them were ok. Some cold solder joints were re-soldered with fresh tin and a Preventive Maintenance was done with pressured air.
The SMPS was put into functioning and look at the results in the photos below. All the volt-out was correct.

atx 500wattrepair2

Now I have a SMPS in my workshop to test any computing device I need to check.












This article was prepared for you by Humberto Rodriguez, one of our ‘Master Authors’ from Cuba.

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  1. Albert

    June 25, 2015 at 2:24 pm

    Hi Humberto,
    Congrats ! Nice job! 500 Watt is really something powerfull for the Testbench in your Electronic repair shop.
    I have such an identical Power Supply with 2 primary Big Filter Electrolyt 200 Volt Capacitors. They are probably cheaper to manufacture and more powerfull than the old 400 Volt single Capacitor Ones. I already replaced three (!) completely defect 4.7uF 50 Volt capacitors in this by a SG6105DZ 20 pins IC driven controller, ATX 410-212 High Power Supply. It still has a malfuction in one of its other components. Replacing the controller ic did not make any difference either. So I think repairing this one is not gonna happen.

    • Humberto

      June 25, 2015 at 8:30 pm

      Well Albert, if you repair it, let us know and post it in this blog.

      By the way, you sent to me by means of Mr. jestine Yong a project with a PC SMPS, and I'd like to use this 500 watts SMPS to do it. Thanks.

      • Albert

        July 1, 2015 at 6:20 am

        Hi Humberto, Yes that nice Power Circuit TestBench Adapter should easily work. But since even the 3.3 Volt Output can generate High Currents up to 25 Amps or more, be Carefull not to Short Circuit your Lab equipment. Or maybe use some kind of Current Limiter inbetween your Test Lab Power Supply and your Devices you want to repair. Afterall 500 Watt is Current Overkill I guess?
        I wouldn't want you to destroy anything by blowing away those thin Copper Layers to Kingdom Come. Maybe I've also some easy Current Limiter Circuit laying around here somewhere.

  2. Robert Calk

    June 25, 2015 at 3:36 pm

    Good job, Humberto.

    • Humberto

      June 25, 2015 at 8:01 pm

      Thanks Robert.

  3. Waleed Rishmawi

    June 25, 2015 at 6:34 pm

    good Job my friend. I used one like that in my shop. it provides 5 volts, 12 volts and 3.3 volts. a very useful power supply in the shop.

    • Humberto

      June 25, 2015 at 8:06 pm

      Yes Waleed, I really want to use it as a DC Power Supply for appliances which need to be repaired.

  4. Gerald

    June 25, 2015 at 8:07 pm

    Well done Humberto.

    • Humberto

      June 25, 2015 at 9:06 pm

      Thanks Gerald.

  5. Shekar

    June 26, 2015 at 12:52 am

    Nice job

  6. Merlin Marquardt

    June 26, 2015 at 3:18 am

    Very nice.

  7. mahmoud

    June 26, 2015 at 4:44 am

    dear Humberto thanks it is a good job for me.

  8. Benjamin E.

    August 4, 2016 at 9:40 pm

    (And anyone else)

    Hey, I know this was posted a little more than a year ago, but I just stumbled across this.

    First off, that power supply is a fake/copycat Delta Electronics PSU. The real Delta supplies are constructed much better than this one, and are much more reliable as well.

    That PSU you have there, judging by the generic looking construction, probably is only good for about 200W to 250W maximum. Maybe 300W on a good day. Those cheap PSUs almost always lie about their power output capability!

    Also, here is the important bit:
    Beware when you find only one of the voltage-doubler caps failed, as you did here.

    It fails either because the voltage across the voltage-doubler capacitors has become unbalanced, or it is just a regular low-quality capacitor (or it is old). When the voltage becomes unbalanced, it causes one capacitor to get too much voltage. This can happen when one of the bleeder resistors goes open-circuit. Be sure to check that, otherwise it might fail again!

    I know this because I helped someone on an electronics forum fix their misbehaving PSU. One of the voltage-doubler caps had failed, and when they replaced it, the problem resurfaced a few weeks later - the new capacitor was now bulged as well! After thinking about it, I had the sudden realization that it could be the bleeder resistor had failed (open-circuit), and indeed it was! 🙂

    Also, another cause of voltage imbalance could in fact be the OTHER capacitor! I know, it sounds weird, but get this:
    When the leakage current in one capacitor becomes too high, it can cause the other capacitor to get too much voltage! Capacitors that read abnormally high in capacitance, often (if not all the time) have an excessively high leakage current. The extra leakage current simply makes it take longer to charge up, hence the high capacitance reading. You can try this for yourself with a known good capacitor, by placing a resistor in parallel with the capacitor being tested. (The resistor can be anywhere from 10K to 1M or more. It depends on the current your capacitance meter puts out.)

    I bet you've come across this kind of a failure before, seeing as all of you repair so many items. But I just thought you'd like to know, in case you didn't know already. 🙂



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