Help wanted... lightning strike wreaks havoc on power supplies!

Discussion in 'General Electronics Chat' started by Capri335, Nov 29, 2014.

  1. Capri335

    Thread Starter New Member

    Nov 29, 2014
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    Cicuit board 1.jpg
     
  2. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    I assume this was just information that you wanted to share. Interesting and thank you for posting. Let us know if you have a question.

    I also like that the board was made by SKYNET Electronics! Considering SKYNET is involved, are you still sure it was lighting?
     
  3. Capri335

    Thread Starter New Member

    Nov 29, 2014
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    Hi everyone, I am in need of some help to try to see if I can salvage a really good (and expensive to replace) machine that we were using daily.
    We got struck by lightning last week. It seems that every appliance that was plugged in (some switched on, but not all) have bitten the dust. In nearly every instance it has been the power supply to each appliance or machine.
    Most are replaceable and some already have been, but our large laminator is old and doesn't work. It doesn't have a separate power supply.
    We found a 240V 2A fuse on the input board (which I am assuming is a power supply). I couldn't find a matching fuse, so I drilled out the ends and used a 240V 2A wire from another fuse. I carefully soldered the wire in and replaced the fuse, BANG. It lit up like a flash light. That tells me that something else has failed. I am wondering what the most likely component to fail would be? The manufacturer is in the USA, this is a really old model and I am in Australia. I am wondering if there is a quick fix. Any ideas? see photo. Please note I am not an electronics person, I can tell a transformer from a resistor and capacitor, but I don't know electronics. As I used to wire up amplifiers I am sure that replacing components would be easy for me. Diagnosing the fault is really beyond me. I do have a multimeter (or two).
     
  4. Capri335

    Thread Starter New Member

    Nov 29, 2014
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    I did have that there in the post first.... maybe I hit a wrong button!
     
  5. wayneh

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    Sep 9, 2010
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    For starters, that fuse looks blown.
     
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
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    I am surprised it did not take the MOV (R1) out!. It is there to protect causes such as this.
    First check the Heatsinked power devices, worse case scenario, it can impose a short on one of the switching transformers.
    Max.
     
  7. GopherT

    AAC Fanatic!

    Nov 23, 2012
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    You cannot just solder in the wire from a working fuse. The glass and oxygen free partial vacuum is there for a reason.
     
  8. Capri335

    Thread Starter New Member

    Nov 29, 2014
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    I said that I replaced it and it blew again.
     
  9. Capri335

    Thread Starter New Member

    Nov 29, 2014
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    Ah OK, thanks I'll have to get to the electronics shop tomorrow. I thought that the glass was just an insulator. House fuses can be either way...
     
  10. GopherT

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    Nov 23, 2012
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    The big transformer in the center looks iffy. also, the chip in the center is an item that tends to fail. Sk8085 available on eBay from sellers in China for $5 to $10 with shipping.
     
  11. bwilliams60

    Active Member

    Nov 18, 2012
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    Is it me or does VR1 look like it got pretty hot?
     
  12. GopherT

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    Either it got hot or it was trimmed at the factory and a low-quality epoxy was dabbed on to keep it in position.
     
  13. ISB123

    Well-Known Member

    May 21, 2014
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    That pot looks melted which probably means that large current passed through it which could mean that Voltage regulator is dead too.
     
  14. takao21203

    Distinguished Member

    Apr 28, 2012
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    nevver heard of that
     
  15. takao21203

    Distinguished Member

    Apr 28, 2012
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    not entirely sure about that
     
  16. ISB123

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    May 21, 2014
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    You are right on one picture it looks like its melted but its actually glue.
     
  17. Capri335

    Thread Starter New Member

    Nov 29, 2014
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    Yes it is just glue on that. Yesterday I managed to get another fuse (bought a pkt of 10), and it blew again. My feeling is that the transformer has probably gone. I am also guessing that it has to be de-soldered from the board before I can test it. I think that the logical thing would also be to NOT connect this board to the next one so that I isolate that probability of some component in the next board causing it.
     
  18. ISB123

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    May 21, 2014
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    This could be your problem marked in red circle,looks like pad fell off or its just weird reflection.
    [​IMG]
     
  19. JWHassler

    Member

    Sep 25, 2013
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    That "input board" is a power-supply. It's way past time to declare a 'quick fix.'
    Figure out the required voltage/current and buy a new one. Don't waste any more time on trying to fix it.
     
  20. Capri335

    Thread Starter New Member

    Nov 29, 2014
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    That's what I was wondering... if it is possible to replace this with another power supply. The only problem here is that I wouldn't really have a clue what to ask for or to order. I am guessing that the transformer lable holds the clue. 240V AC .5 amp in and 24V DC 1.3 amps out. There are only 2 wires into this and 2 wires out. As for working it out, that is a bit beyond me. The other board that it plugs into has no values on the input side, other than "DC".
     
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