No Gas welder

  1. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    My powercraft no gas welder stopped working. When I opened the top the wire had run out. I replaced the wire and the welder still did not work. I found a loose wire in the torch handle and the machine came to life but the wire feed won't work. I disconnected the motor and it works on a battery. The motor works and the drive wheel moves. When it's reconnected no wire feed. I am no expert on repairs could anyone give me any advice on how to proceed?
    Powercraft Mig welder 25-130amps
     
  2. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,414
    Location:
    Skelton in Cleveland U.K.
    Tell us a little about yourself, and the welders intended use, repairs projects etc, I'm sure one of our members well versed in the inner workings of your machine will post shortly.
     
  3. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    Thanks for the reply. I am new to this so I don't know what I am doing. I am retired just doing some DIY in the garden. I have had the welder for a few years and it's been ok up to now. It' had very little use and the fault just appeared when the wire ran out
     
  4. gordon stephenson

    gordon stephenson Forum Supporter

    Messages:
    6,414
    Location:
    Skelton in Cleveland U.K.
    Im sure someone will reply soon, There are some very clever and diverse members here and understand the inner workings of welding sets, Im more of a mechanical person and the electrics are just "white mans magic" me.
     
  5. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    I have now disconnected the motor and tested it on a battery and its ok. I have now connected a voltmeter across the wires that feed the motor and I get NO voltage when I press the trigger. I am now lost on what to do. Can anyone help?
     
  6. mike 109444

    mike 109444 Member

    Messages:
    4,086
    uk Bristol
    Can you post a (nice clear) pic of the pcb as then will try and advise what and where to check
    And welcome BTW :hug:
     
  7. Bill Edwards Member

    Messages:
    4,815
    Location:
    Scarborough, North Yorkshire
    Good pictures would be handy, it could be something like a failed relay - see if you can trace the wires that connect to the motor and tell us where they connect to on the circuit board, it'll give a starting point.
     
  8. mike 109444

    mike 109444 Member

    Messages:
    4,086
    uk Bristol
    Does it look like this PCB ?
     
    • pcb 1.jpg
  9. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    Hi Mike Thanks for the response. The picture is of the same board as mine. The machine now comes on and will arc but the motor will not go to feed the wire. No voltage to the motor. The motor works when I put a battery across it. I have AC voltage on the panel which seems to go to the yellow transformer (one leg) I am not tech so I am now lost as to were to go now. I would be grateful for any help
    Thanks
    Dave
     
  10. mike 109444

    mike 109444 Member

    Messages:
    4,086
    uk Bristol
    Looking at the under side of the pcb I believe that the AC 240 goes in to the transformer on pins A and B and then the low AC voltage out is on pins C and D or E not sure which as the track must be on the other side. If you meter between A and B do you get 240 Volts AC ? If yes then meter for 15 to 30 Volts AC at C and D or E.
    Which pins do the motor connect to ?
    Can you get a fuller pic (than mine) of the pcb.
     
    • pcb 2 UNDERSIDE.jpeg
  11. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    Thanks for that. I assume that I am measuring right. I have now checked that I have 240 volt ac on the transformer. If I check the two outer pins on the other side I get about 30 volt ac. Were do I go from here?
     
  12. mike 109444

    mike 109444 Member

    Messages:
    4,086
    uk Bristol
    Right so you have the LOW AC voltage (the 30 volts) onto the board. This now gets changed to DC. The black round thing on left side of board viewed from component side (It's a bridge rectifier) If you look at it, it has a " + " and a " -" and two squiggly lines. The squiggly lines indicate the AC IN to it (from the 30vAC) the device then changes it to DC and it comes out on the + and - pins. Check to see if you have the AC in (meter set to AC) if yes then check for the DC out (meter set to DC volts ).
     
  13. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    I assume its the one marked D2 on the board. I don't appear to have any voltage readings. Should it at least have a reading if I am getting a reading at the transformer. Does that mean that it needs to be replaced If so were would I get such a thing to fit in it's place
     
  14. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
     
  15. mike 109444

    mike 109444 Member

    Messages:
    4,086
    uk Bristol
    You should see the 30v AC at the inputs to that device (D2) at the very least, unless the output from the transformer goes through one of the relays in which case you might need to operate the trigger at the same time (not easy to do by your self!)
    Remember I am only working this out form the pics I have posted as I don't have a better image. It really needs a pic of both sides with that black plastic (?) frame removed as this is a double sided pcb the tracks start on one side and may continue on the other making it difficult to work out what is connected to what.
    Do you hear any "click" from the pcb when the trigger is pulled ? and again which pins do the motor connect to ????
     
  16. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    Yes I hear a click when trigger is pulled. The pins 6& 7 go to the motor. I will try to measure again and press the trigger. Once again thanks for your assistance
     
  17. The very first thing to check if you have any sort of wire feed motor issue is the torch trigger. Try disconnecting the wires to the trigger, and then connecting them directly together.
     
  18. mike 109444

    mike 109444 Member

    Messages:
    4,086
    uk Bristol
    If you meter on the two pins marked "X X" (meter set on DC volts) do you get 12 Volts ?
    Also what is the numbers on that relay G??? 14 as the pic is not clear enough
     
    • pcb 2 UNDERSIDE.jpeg
  19. rotivator

    rotivator Member

    Messages:
    18
    Location:
    Cornwall UK
    Have now rechecked the voltage on D2. I have AC on one side and DC on the other when the trigger is pressed
     
  20. mike 109444

    mike 109444 Member

    Messages:
    4,086
    uk Bristol
    Right so do you have 12Vdc at the relay as asked in post 18 ?
     
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