CIRCLE PC ATX SMPS Model CPH698 Repaired

 

 

 

 

 

Received Circle PC ATX SMPS for Repair from one of my techie friends, Stating fault symptom: Dead

 

Connected SMPS to Power & shorted PS_ON pin (Green Wire) to ground (Black) wire on ATX Connector by this shorting SMPS FAN should Spin & there should be output Voltages on the Connector. But here FAN is not spinning and no any output voltages.

So for testing the SMPS I opened it, found SMPS full of Dust. By wearing face Mask I cleaned the SMPS from the inside.

After Cleaning the SMPS I checked Fuse, found OK if fuse is Ok and No power indicates some Open circuit in the Primary side.

So for further testing, for safer side I connected SMPS on Series Bulb Tester Board, I found No Voltage on Standby (Purple) wire & PS_ON (Green) Wire, it should be +5v & it is showing 0v.

Checked AC Voltage input to bridge diode it is showing 270v seems OK but Diode O/P voltage is Fluctuating.

Here I decide to check all primary side Components on cold testing. Because if voltage fluctuation is because of some shorting, fuse have to blow. but here fuse is intact.

So first Removed MJE13009 NPN primary switching Transistors for testing seems Good, 

Now Here PWM 7 Pin IC JD3313D is used & it is not available in local market. I already have some SMPS lying with me which have not been repaired due to non-availability of this IC.

Now started checking components one by one around PWM IC. On testing resistor, I found there are two Resistors used in series for soft start for PWM IC both are 1.5MΩ one resistor on PCB is showing some fluctuating Value. May be capturing Circuit impedance of surrounding components. Hence removed resistor one by one and checked.

One resistor is showing 1.4MΩ & second one is showing No reading indicates Open circuit. Checked another surrounding resistors & diodes shows OK. So I took one 1.5MΩ Resistor from my salvaged parts Box.

Checked it is showing 1.47MΩ.

Replaced Resistor on its place & soldered back all removed part & powered the unit for testing using Series Bulb Board.

Checked Voltage on PS_ON wire now it showing 5v.now triggered the PS_ON (Green Wire) by shorting to Ive Black wire. Found FAN is Spinning.

& SMPS is back to the Life. Connected it on another setup for testing it works fine & it is ready to pick up. 

This article was prepared for you by Yogesh Panchal who works as a Computer Hardware Engineer in Mumbai India.

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Note: You can check his previous repair articles on Laptop Repaired for Blue Screen Error

 

20 Comments

1. 

   ANTHONY PATERSON

   September 13, 2025 at 5:53 pm

   Clear description of your testing strategy which will be useful and informative to others. Thank you for sharing.

   Likes(2)Dislikes(0)

   Reply
   • 

     Parasuraman S

     September 13, 2025 at 7:56 pm

     Thanks for sharing my favorite SMPS service work having a different problem which I have never faced so far! Good job done!

     Likes(4)Dislikes(0)

     Reply
     • 

       Yogesh Panchal

       September 14, 2025 at 2:01 am

       Thank you!Sir

       Likes(0)Dislikes(0)

       Reply
   • 

     Yogesh Panchal

     September 14, 2025 at 1:59 am

     ANTHONY PATERSON, Thank you! for your encouraging feedback.

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     Reply
2. 

   Andy Shiekh

   September 13, 2025 at 9:33 pm

   Nice catch

   Likes(0)Dislikes(0)

   Reply
   • 

     Yogesh Panchal

     September 14, 2025 at 2:02 am

     Thank You!Andy Shiekh

     Likes(0)Dislikes(0)

     Reply
3. 

   tree

   September 13, 2025 at 9:42 pm

   Where can I find the circuit for this or other power supply?

   Likes(0)Dislikes(0)

   Reply
4. 

   Albert van Bemmelen

   September 13, 2025 at 11:25 pm

   Always interesting to read about service on new smsps repairs. 20 of those JD3313D pwm controllers are about 15 euro on Aliexpress. On which a third of the price is for shipping alone. But a datasheet is hard to find. If needed we always can try the universal modules that are often used by dear Parasuraman. Thanks for sharing!

   Likes(1)Dislikes(0)

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   • 

     Yogesh Panchal

     September 14, 2025 at 8:12 pm

     Albert, Thanks! for your input. i will try with external universal modules because i have almost 12 ATX SMPS laying in my storage,because of unavailability of these both PWM IC JD3313D & 8117C 7 DIP-7 pins, chines web portals like Aliexpress is Blocked in our country due to some political conflicts.

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5. 

   Mendis

   September 14, 2025 at 12:29 am

   Very nice article brother,clearly explain

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   • 

     Yogesh Panchal

     September 14, 2025 at 8:13 pm

     Mendis, Thanks!

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     Reply
6. 

   Yogesh Panchal

   September 14, 2025 at 2:05 am

   Tree,
   https://danyk.cz/s_atx_en.html

   Likes(1)Dislikes(1)

   Reply
7. 

   Mark J

   September 14, 2025 at 2:35 am

   Yogesh good article . Well done on the repair.

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   Reply
   • 

     Yogesh Panchal

     September 14, 2025 at 8:14 pm

     Thanks! Mark J

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     Reply
8. 

   Mark

   September 14, 2025 at 8:33 am

   Good job Yogesh

   Likes(0)Dislikes(0)

   Reply
   • 

     Yogesh Panchal

     September 14, 2025 at 8:14 pm

     Thanks!Mark

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     Reply
9. 

   tree

   September 14, 2025 at 1:54 pm

   To prolong the life of the power supply, the surrounding electrolytic capacitors should be replaced.

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   Reply
10. 

    Yogesh Panchal

    September 14, 2025 at 8:56 pm

    Tree,
    What if the problem reoccurs even after replacing all the surrounding parts? No one can predict the behavior and life span of a any component.can anyone predict that this unit is not going to fail again after replacing all the parts?simply replace the faulty components required to repair that particular fault.

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11. 

    Tito Kanshulu

    September 18, 2025 at 5:45 pm

    Good repair article Yogesh. It, indeed, requires expert hands to identify such a high value resistor. Keep the good work

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    Reply
12. 

    Yogesh Panchal

    September 19, 2025 at 4:24 pm

    Thank You! Tito Kanshulu

    Likes(0)Dislikes(0)

    Reply

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