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Power Supplies a cautionary tale

Discussion in 'Power Supplies' started by Parkside, May 14, 2011.

  1. Parkside

    Parkside New Elf

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    Thought it worth flagging these up, no names on the supplier, they took the issue seriously as well , don`t believe they stock this type of supply any longer.

    But should you encounter one out in the wild , HP power supplies, not that HP, those people at Hong Peng, 5V 6A power supply.

    Had a batch of them in, first one goes bang, literally, spike takes out a dimmer on the same ring at the time.

    Second one goes on isolated workshop supply and oscope, starts at around 30V then settles over a few seconds to around 4.6V with about a volt of sawtooth ripple superimposed.

    Third one gets the lid opened:

    http://dl.dropbox.com/u/28439610/IMAG0727.jpg

    http://dl.dropbox.com/u/28439610/IMAG0729.jpg

    http://dl.dropbox.com/u/28439610/IMAG0733.jpg

    Yup, it looks like a power supply recovered from the Titanic , the muddy crud is OEM crud...

    Common mode choke is missing and couple of nuts on the heatsink means they have actually been adapted after being recovered from bottom of a puddle..

    There is quite a lot of energy in a switch mode power supply, some the components can be run under quite a lot of stress, its probably worth not cheaping out on PSUs...

    Cheers
    Adam
     
  2. mrpackethead

    mrpackethead Full Time Elf

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    that may be a contender for the "scary" prize.
     
  3. AAH

    AAH I love blinky lights :) Community Project Designer

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    If that isn't a dry solder joint on img 733 on the pad adjacent to the blue MOV visible through the hole then it probably soon would be. pretty ironic when it looks like the whole pcb has been wet ;)
     
  4. fasteddy

    fasteddy I have C.L.A.P Global Moderator Generous Elf

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    Thats a great example of the varying quality and controls coming out of China, with this one being a great example of how bad it can be.
     

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