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Saving Computer SMPS Part – 12

By on February 2, 2025
Saving Computer SMPS Part – 12

 

 

 

 

 

 

 

Saving computer SMPS (ATX Power supplies) holds the first priority in my interest in electronics, mainly because of the wonderful book published by Jestine Yong on servicing SMPS. Here are two more computer SMPS of Hospital where I work, saved from dump.

Case (1) Zebronics-ZE450W : This was brought dead and I found that capacitors were burst and there were a lot of dry solders. The dust was cleaned by the administrator himself before giving, saving my time. The tank capacitors showed way out of range when checked.

how to repair atx power supply

The steps that I follow in such cases are (1) Checked fuse, found ok. (2) Did ring test on all the three transformers and found these to be ok. So, replaced all the electrolytic capacitors on the board and retouched all the points with fresh solder.

Cleaned and lubricated the fan. Then the SMPS was found working with healthy voltages on a load of 25W, 12V bulb:

fixing atx power supply

Case (2) Foxin FPS500+ : This was yet another after warranty SMPS reported to be dead. I could not find any capacitor bulged in this. But there were dry solders to such an extent that the joints were separated from the board:

dry joint

The tank capacitors showed way out of range and gladly I replaced all the electrolytic capacitors on the board:

how to fix atx power supply

I am not sure whether you all can view the readings. One was showing 238.8uF with an ESR of 0.21 Ohms and the other was showing 229.5uF with an ESR of 0.04 Ohms.

After retouching the board thoroughly and subjecting it to cleaning with IPA, the SMPS was found working very well on a similar load and I allowed it to run for some time before closing the covers.

how to repair a broken atx power supply

Double missions accomplished with double satisfactions getting added to the collection, and the avaricious bag looking for more and more! (LOL)



P.S. I used to wonder what would have happened to me if I had not got this craze in electronic servicing, which is keeping me going in full cylinders even at such a late stage of life! It makes me a child with a lot of vigor and enthusiasm which I think nothing else can give! Every accomplishment, however trivial it might be, are a thrill and propagation pushing me further and further!

parasuramanphoto

This article was prepared for you by Parasuraman Subramanian from India. He is 74 years old and has more than 30 years’ experience in handling antique equipment like Valve Radio, Amps, Reel Tape Recorders and currently studying latest tech-classes conducted by Kerala State Electronics Technicians’ Association. He has done graduation in BBA degree, private diploma in Radio Engineering and retired as MD of a USA company. Presently working as Consultant to Hospital and other institutions.

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You may check on his previous article on Uneconomical Repair Necessitated Replacement Of Board Once More In Samsung CRT TV

 

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22 Comments

  1. Albert van Bemmelen

    February 2, 2025 at 6:57 pm

    Another well done smps units repair article with a lot of e-caps out of spec as usual!
    About having this hobby, someone said to me that it must be a man's thing because women probably consider us to be technical nerds. But I have no doubt that your social skills are more advanced to be just that especially compared to mine (lol).
    And I completely understand your drive in wanting to keep doing electronics repair as a very satisfying hobby.

    Likes(2)Dislikes(0)
    • Parasuraman S

      February 2, 2025 at 9:12 pm

      Ha! Ha! Very entertaining comments! Thanks, dear Albert!

      Likes(1)Dislikes(0)
  2. Yogesh Panchal

    February 3, 2025 at 12:22 am

    Good Job!Sir,
    The stage of life is a myth,as long as our creativity is alive and we have proper Hunger to learn and do something new."Stage" is the only platform, where we get the chance to perform & prove ourselves.

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 3, 2025 at 3:24 pm

      Excellent comments from deep introversion! Deep meanings! Many thanks!!

      Likes(0)Dislikes(0)
  3. Kevin Davison

    February 3, 2025 at 12:24 am

    Parasuraman you are quite often the highlight of my weekend. I thoroughly enjoy reading through your repairs. I always learn something.

    Likes(3)Dislikes(0)
    • Parasuraman S

      February 3, 2025 at 3:25 pm

      Many thanks for your wonderful and encouraging comments! It really boosts me up!

      Likes(0)Dislikes(0)
    • Mark J

      February 4, 2025 at 3:49 am

      Kevin that is true I always learn something from his articles.

      Likes(1)Dislikes(0)
      • Parasuraman S

        February 4, 2025 at 5:23 pm

        Very nice of you, dear Mark! You are always supporting and encouraging!

        Likes(1)Dislikes(0)
  4. Mark J

    February 3, 2025 at 1:28 am

    Parasuraman another great SMPS repair. All of you guys on here inspire and drive me to keep doing electronic repairs.

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 3, 2025 at 3:26 pm

      Many thanks! Jestine Yong's this forum is really an inspiration for electronic technians!

      Likes(1)Dislikes(0)
  5. Henrique J. G. Ulbrich

    February 3, 2025 at 4:25 am

    I make your words my own. As a matter of fact, electronics is in my blood. I am also next to complete 80, without losing the enthusiasm.

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 3, 2025 at 3:28 pm

      That's great! You are much senior! My salutations! Many thanks!

      Likes(0)Dislikes(0)
  6. Imoudu

    February 3, 2025 at 5:40 am

    Perhaps if you have not being in electronics repairs buz, you would have been in electronic research institute as an inventor...you carry electronics blood in your arteries...Lol

    Do e-cap have capacitance tolerance %+/-?

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 3, 2025 at 3:30 pm

      Many thanks for your wonderful and encouraging comments! Yes, there is tolerance for every electrolytic capacitor! Normally it is 5 to 10%.

      Likes(0)Dislikes(0)
  7. Waleed Rishmawi

    February 4, 2025 at 3:09 pm

    age is like wine, the older the better...LOL. a friend of mine told me that once and ever since I am trying to push myself further. thanks for the articles and it kind of strange to me that all the computer power supplies usually have either dry joints and bad caps and I wonder why that is? I do not see bad ic's or anything els..have a blessed day

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 4, 2025 at 5:26 pm

      Makers indulge in cost saving methods to make their products competitive, but compromise on quality. Anyhow, they indirectly help us all, technicians, to earn our bread through such repairs, don't they? Many thanks for your wonderful comments, dear friend!

      Likes(0)Dislikes(0)
  8. MUYKIT

    February 6, 2025 at 6:55 pm

    Engineer Parasuraman, I say this was an almort perfect explanation because I'm not told of what the wrong esr readings of the tank capacitors should have been. Now concerning age, Ulbrich and you indeed exemplify that technicians 'never go home'. Even if you go customers still come home and insist that you make repairs for them or even just seek your technical oppinion or advice about an issue. I've seen it among my old techie friends who even changed careers. You see, once a soldier, always a soldier. As for me I'm 55 but I already feel worn out, occationally dragging with assignments. But I just have to struggle on like everybody else because electronics repair is sometimes really interesting and enjoyable. But on a bad day all working plans may hit a brick wall. Thanks, you old boys of electronics, dont 'go home' yet.

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 9, 2025 at 5:27 pm

      Very true, dear! Hard facts of life and we are programmed to face it! Thanks!

      Likes(1)Dislikes(0)
  9. MUYKIT

    February 7, 2025 at 7:00 pm

    Once more thanks Engineer Parasuraman for finding time to teach us. I hope you will let me know what the correct ESR value(s) of the tank capacitors should have been. You have plainly expressed how deep your interest liEs in SMPS repair. For me I had to keenly follow your past articles on CRT TV repair because most of them were, as I had earlier on found out, neglected on grounds of SMPS failure. Operating in a rural area wasnt going to deny me a learning opportunity. So, I shamellessly but purposely ventured to work on near obsolete CRT TV boards that had SMPS. They were easy to come by, they'r mostly ignored. I intended purely to put my ability to test on some repairable SMPS. Some TVs came on after a long repair struggle. I'm still learning though. Lets aquire skills fairly in any possible way. Pricy precious gold can be taken away from you, but not knowldge.

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 9, 2025 at 5:29 pm

      The standard values of ESR is available for view if you give a search in the web. I think, even our Jestine Yong had published it.

      Very true statements of life and experience! I agree with you! Many thanks, dear!

      Likes(1)Dislikes(0)
  10. MUYKIT

    February 8, 2025 at 1:05 pm

    I DID NOT MEAN TO SEND MY COMMENTS TWICE, IT'S JUST THAT I THOUGHT I HAD SEND THE FIRST ONE WRONGLY AND SO YOU HAD'NT RECEIVED IT. I SHOULD BE CAREFUL ABOUT MULTI-TASKING. ALL THE SAME THANKS TO YOU ALL MY DEAR TECHIE FRIENDS WHO LIVE NEAR ME OR THOUSANDS OF KILOMETERS FROM MY COUNTRY KENYA.

    Likes(1)Dislikes(0)
    • Parasuraman S

      February 9, 2025 at 5:30 pm

      Never mind! Good things can be repeated! Ha! Ha!

      Likes(0)Dislikes(0)

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