Sealey supermig 180 died !

  1. wacky7791

    wacky7791 Member

    Messages:
    216
    Location:
    SEQ australia
    this all looks a bit iffy, relay J2 and the three fuses or resistors below it, unless its just muck. poss short on the transistor close by?


    upload_2020-4-10_8-48-9.png
     
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  2. Nigee161 New Member

    Messages:
    16
    Location:
    GOSPORT Hampshire
    Thanks Eddie49 ,
    There is no over heating light on and never has been. On checking the wires you described there is 26v , 18.6v , 18.6v , 26v.
     
  3. eddie49 Member

    That is good. It means we have AC mains, there's no blown fuse, the auxiliary transformer primary is OK, and the secondary output voltages are correct. ( I don't know why it needs all those outputs, most auxiliary power supplies are a straight single 24v.... )

    On your PCB, the relay that gaz1 referred to is not in a transparent plastic case, it is the moulded black plastic block with a brown and a red wire connecting by push-on tags. This relay switches the live mains in to the main welding transformer. It is controlled by the torch trigger switch, via the logic on the PCB. The contacts on these relays have a hard life, and that relay is quite a small version.

    To bypass the relay: disconnect the machine from the mains, pull off the brown and the red wires from the relay, and join them together. They are push-on car-type tags. Insulate the join - this is live 230v mains! Select a low power setting on the range switch. Plug in the welder and turn on the on/off power switch. Because the relay has been bypassed, the main welding power should come on immediately, as though you had pressed the torch trigger. See if you can get an arc between the welding wire at the torch tip and the ground clamp. I doubt if the gas solenoid or the wirefeed motor will come on, but try pressing the torch trigger switch and check for that.
     
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  4. Nigee161 New Member

    Messages:
    16
    Location:
    GOSPORT Hampshire
    Just tried that bridged the two wires and turned it on to number one, nothing happens pulling the trigger but it sparks out touching the torch end wire to the earth clamp
     
  5. gaz1

    gaz1 Member

    Messages:
    11,366
    Location:
    westyorkshire
    now try it with those being plugged back in

    if theres power again when you pull the trigger then it shouldnt be the large transformer side of it

    but the controlling side for the motor

    that test above tests for power at main transformer and a direct connection to earth like it would when the wire hits the material being welded
     
  6. Nigee161 New Member

    Messages:
    16
    Location:
    GOSPORT Hampshire
    Plugged them back in and turned on machine. Nothing happens when pulling trigger no wire feed etc. It still arcs out though if I touch the wire tip to the earth clamp
     
  7. eddie49 Member

    The main transformer is OK, and so is the auxiliary transformer.

    The PCB contains diodes to rectify the 18v and 26v AC that you measured. There is logic to control the relay, and a speed controller for the wirefeed motor.
    None of this is working, it does look like the PCB is faulty. Further troubleshooting at the component level is possible, but not easy since we do not have a circuit diagram and the components are surface-mount ( SMD ), rather than through-hole. This company ( Tec-Arc in York ) offers a mail-in repair service for the Sealey PCB:
    https://www.ebay.co.uk/itm/SUPERMIG-185-MIG-WELDER-CONTROL-PCB-REPAIR-SERVICE/113731613302
    If you decide to go that route, maybe you should contact them to confirm that they are open, and that they can deal with an SMD board.
     
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  8. Nigee161 New Member

    Messages:
    16
    Location:
    GOSPORT Hampshire
    Okey dokey many thanks for all your time and knowledge very much appreciated
     
  9. a111r Member

    Messages:
    903
    Location:
    London
    The Tec-Arc photo is of the older type of pcb, with 'thru-board' components, not smd. See what they say.
    A replacement from Sealey is £82 plus vat, so it's not that much more.
     
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  10. Nigee161 New Member

    Messages:
    16
    Location:
    GOSPORT Hampshire
    Many thanks for your time and knowledge as well sir , much appreciated
     
  11. anjum Member

    Messages:
    1,207
    Location:
    London UK
    AFAIK It's actually mixed technology IC's are through hole diodes resistors etc are smd.
    If there's an identifier to the version of the board tell them when you contact them so you get the right or compatible pcb.
     
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  12. Nigee161 New Member

    Messages:
    16
    Location:
    GOSPORT Hampshire
    Hi peeps
    Just an update , received the new pcb all fitted and working well. Many thanks for all your help much appreciated
     
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  13. eddie49 Member

    Thank you for the update, and I'm glad it is all fixed.
     
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