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    450w ATX smps switching voltage low

    some time with load / when connect to mother board SMPS not on,
    in that time remove all connector from mother board - green pin voltage under 2.5 volt, after wait 1 or 2 day when again power on without load, green pin voltage is ok for switch on the SMPS...
    What can i do now, & where I am check it






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    Re: 450w ATX smps switching voltage low

    Hello dey4su,
    What is the part number of the integrated circuit underneath the mains input filter PCB?
    Regards,
    Relayer



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    Re: 450w ATX smps switching voltage low

    Quote Originally Posted by Relayer View Post
    Hello dey4su,
    What is the part number of the integrated circuit underneath the mains input filter PCB?
    Regards,
    Relayer
    Bridge IC = GBU 606

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    Re: 450w ATX smps switching voltage low

    You did not give any clue of the brand/model of this equipment. Anyway, some cheap low-quality power supplies do not work well with no load connected; In general the 5v is used as internal reference for the loopback control, and it is advisable to put a minimal load there.
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    Re: 450w ATX smps switching voltage low

    Quote Originally Posted by andre_teprom View Post
    You did not give any clue of the brand/model of this equipment. Anyway, some cheap low-quality power supplies do not work well with no load connected; In general the 5v is used as internal reference for the loopback control, and it is advisable to put a minimal load there.
    hi, its working last 1year 8months. but now arise the problem.. ..
    Company = i ball
    Marathon - 500W Peak

    What you think, any component is need to change ??




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    Re: 450w ATX smps switching voltage low

    They are not the manufacturer, it's just the name they put on it that day. The next day it would have a different branding. That way nobody can go back to complain if it breaks down!

    Andre is quite right, it should be tested under load. I suggest wiring a car headlight across the +5V and 0V outputs. It will not run at full brightness but it should draw an Amp or so to keep the PSU feedback happy.

    I find most intermittent start up problems are caused by electrolytic capacitors in the input stage drying out and dropping in value. I think they are marked EC10 and EC13 in the photographs. Change them with new ones rated for 105C and the same value and working voltage. Don't try to test them, just replace them, they only have a life expectancy of a few years in a PSU like that and they cost very little.

    Brian.
    PLEASE - no friends requests or private emails, I simply don't have time to reply to them all.
    It's better to share your questions and answers on Edaboard so we can all benefit from each others experiences.


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    Re: 450w ATX smps switching voltage low

    Quote Originally Posted by betwixt View Post
    They are not the manufacturer, it's just the name they put on it that day. The next day it would have a different branding. That way nobody can go back to complain if it breaks down!

    Andre is quite right, it should be tested under load. I suggest wiring a car headlight across the +5V and 0V outputs. It will not run at full brightness but it should draw an Amp or so to keep the PSU feedback happy.

    I find most intermittent start up problems are caused by electrolytic capacitors in the input stage drying out and dropping in value. I think they are marked EC10 and EC13 in the photographs. Change them with new ones rated for 105C and the same value and working voltage. Don't try to test them, just replace them, they only have a life expectancy of a few years in a PSU like that and they cost very little.

    Brian.
    thank you for your valuable feedback, after change I will back to you with feedback.



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    Re: 450w ATX smps switching voltage low

    Now SMPS working fine,


    I am changed 3 electrolytic capacitors.
    On the board that value = 2.2uf 50v, but this is not available in our local market, so I replace it with 2.2uf 63v.
    >Before change that Switching voltage in green pin 0.5v, after change green pin voltage 2.9v



    Special thanks "betwixt".




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    Re: 450w ATX smps switching voltage low

    Quote Originally Posted by betwixt View Post
    They are not the manufacturer, it's just the name they put on it that day. The next day it would have a different branding. That way nobody can go back to complain if it breaks down!

    Andre is quite right, it should be tested under load. I suggest wiring a car headlight across the +5V and 0V outputs. It will not run at full brightness but it should draw an Amp or so to keep the PSU feedback happy.

    I find most intermittent start up problems are caused by electrolytic capacitors in the input stage drying out and dropping in value. I think they are marked EC10 and EC13 in the photographs. Change them with new ones rated for 105C and the same value and working voltage. Don't try to test them, just replace them, they only have a life expectancy of a few years in a PSU like that and they cost very little.

    Brian.
    Hello sir, some time SMPS working very good, some time, not working - switching voltage 0.5v
    Which section need to check ?



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