murex trades mig 160

  1. arnycunningham Member

    Posts: 5
    hi all, new to forum,

    i have a tradesmig 160 with a fault that developed since putting the machine away over the winter, came to use it and the motor that feeds the wire has stopped working, a little bit of investigating and i noticed one of the relays wasnt working on the pcb board, the year before the other relay wasnt working but a little tap and it started to operate again and all was well.

    no such luck with this other relay, i removed the plastic cover and gently operated the relay manualy and the wire motor started operating and the variable speed controler operated as it should do to, so i have drawn the conclusion that either the signal to operate the relay is broken somewhere or the relay or component on the board had gone faulty.

    ive checked the board and cannot see damagaed or broken parts or cracks etc, ive checked all wiring with a multimetre and everything else on the wleder apears to be working but not this relay.

    is there a compnonet on the board that could stop the relay working or does it simply mean the relay has failed ?.

    i see lots of people mention changing components on the pcb, this i can do but guideance as to which component does what and where would be needed.

    can anyone point me in the right direction,

    pcb board is a elstra wien w22 4273882 which i beleive is also in the 230 amp machine.

    the welder has always been a bit fragile as to the consistancy of welding, one minute it worked great, go to use it five minutes later and it wouldnt work as it did previoulsy and you would have to adjust settingsda again and so on, i got used to doing this but maybe if this relay or pcb board isnt upto scratch it would be causing my inconsistancy.

    any help or guide would be gratefull, if not does anyone knoe who to trust to check th eboard or sell em another etc.

    thanks all.
  2. arnycunningham Member

    Posts: 5
    just found and i wonder ?

    relay is rl01 which is the relay thats not working.

    i found a resistor thats numbered r26 thats a little scorched on the pcb board and resistor looks burned in colour, coulrs from what i can see are (starting from the left ) looks like a silvery gold colour then two browns and then a green line.

    would this item cuase the relay not to operate if faulty, ?

  3. rtbcomp

    rtbcomp Moderator Staff Member

    Welcome to the forum.

    The colour sequence for your resistor would most likely be Green-Brown-Brown, 510 ohms. The other band is the tolerance, forget what gold and silver stand for. They only cost pence from Maplin. Depends where in the circuit it is whether or not it affects the relay.
  4. NotANormalCoder Fixer of welders for too many years

    Posts: 248
    Surbiton - Surrey
    For what it's worth, I've repaired a lot of these boards and according to my notes, R26 is a common failure and I fit a 1K ohm resistor to fix the problem. Of course, it could be many other things but it's got to be worth fitting a new resistor here first. I can test/fix your board or supply a s/exchange if needed.
  5. arnycunningham Member

    Posts: 5
    thanks for the replies.

    how much to test and repair or exchange board, everything on the welder works apart from the relay not pulling in, if i do it manualy it all works fine, do you know if this r26 is responsible for operating the relay.

    if its not how can i test the component and what is responsbible for making the relay operate ?

  6. arnycunningham Member

    Posts: 5
    ok so today i replaced the compnent that looked faulty, it did still work when tested out of circuit but was reading into the 644 ohm bracket.

    i replaced it with a 1k component and upon further inspection found the original part to have a partialy dry joint, broken but not quite rite through.

    fitted the pcb back into the welder and he presto, nothing, doing exactly the same as before.

    ive been looking at the board some more and a friend who is a tv engineer tested the board components and each one he tested apeared to be fine, the contacts and visual condition of the board looked good.

    but what we cant get to work is the relay which apears to be a magnetic type, i think from what i can see the bottom part of the relay pushes the little bar away and the top part of the relay pulls the bar across therefore making it pivot the top arm and push the contacts across to touch.

    very ocasionaly it tries to move but not fully and wont do it again.

    where can i purchase one of these relays or can i use another type.

    or is there a product on the board that operates this relay, if so which is it.

    thnaks all

    ps does nayone think this could be the lance not sending a signal to the board to operate the relay.

    i need it repaired quickly so help would be good.

    i was thinking of soldering wires to the working side of the relay and running upto the handset and using a micro swith to operate it, a bid heath robinson but it would make the welder work again quickly.
  7. NotANormalCoder Fixer of welders for too many years

    Posts: 248
    Surbiton - Surrey
    So, it could easily be the relay that is faulty, it's simply a 24Vdc Coil, 10 or 16Amp rated relay with 8 pins. Probably available through Maplin, RS Components, Farnell or any other decent electronic suppliers. However, it's also very possible that it's one or more of the transistors, one of the 555 chips or dry joints, so the most sensible/quickest option is a s/exch pcb, which I have sitting here.
    It will not be the signal from the gun switch if the other (contactor) relay is operating when you press the trigger. Also, DO NOT bypass the relay with a microswitch - the relay you have trouble with and the transistor work together to supply power to the motor. If you apply power (by pressing the trigger) and do not operate the microswitch at exactly the same time, the pcb will try to send power to the motor and short itself out at the same time frying the pcb!!
    I am at work on the number I gave you, for most of today, as I am awaiting delivery of a new van. Call me if you want to discuss further.
  8. arnycunningham Member

    Posts: 5
    i would call you if i could find the email section with your details, perhaps you could call me and i call you straight back, or send another mail, it allowed me to read it but i dont seem to be able to retrieve it again.

    asap please thnaks
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