Any ideas? I was going to treat it to a new torch/liner anyway as it seems like it hasn’t been changed for a while. The wire feed feels strong when I press the trigger.
- Thread starter kcchan
- Start date
Any ideas? I was going to treat it to a new torch/liner anyway as it seems like it hasn’t been changed for a while. The wire feed feels strong when I press the trigger.
As well as the wirefeed, the torch trigger should be controlling the gas solenoid and the main on/off Contactor for the welding current.
When the wirefeed stops, does the gas and the arc also drop out?
Can you hear any relays clicking or the Contactor dropping out when the fault happens?
If you slacken the pressure roller so that there is no load on the motor and press the trigger, does the wire drive roller then run continuously?
When the wirefeed stops, does the gas and the arc also drop out?
Can you hear any relays clicking or the Contactor dropping out when the fault happens?
If you slacken the pressure roller so that there is no load on the motor and press the trigger, does the wire drive roller then run continuously?
I've just done some more testing and I believe it is stuck on Spot Welding mode. I can alter the time it runs for but I can't switch it off.
The stitch welding function, I can turn off. I might have a go at swapping the switches over to check that the knob is faulty.
The stitch welding function, I can turn off. I might have a go at swapping the switches over to check that the knob is faulty.
That's an odd fault. It could be the switch on the back of the spot-time potentiometer, or there could be an error on the logic board - a "1" somewhere instead of a "0", which means that the spot function is always enabled.
I don't know if the switch has to be open or closed to disable the spot timer, but you could unsolder one of the switch tags and test the functionality with an ohmmeter.
I don't know if the switch has to be open or closed to disable the spot timer, but you could unsolder one of the switch tags and test the functionality with an ohmmeter.
If the problem is not due to a faulty switch on the back of the spot timer potentiometer, it may be a dry solder joint.
I would suggest unplugging the wires and connectors from the PCB, after noting where they all go, then removing the board from the machine and re-soldering any suspicious-looking joints ( or even all of them ).
This Murex circuit diagram may apply - it does show a spot & pulse timer:
I would suggest unplugging the wires and connectors from the PCB, after noting where they all go, then removing the board from the machine and re-soldering any suspicious-looking joints ( or even all of them ).
This Murex circuit diagram may apply - it does show a spot & pulse timer:
So, I disconnected the switch wires on the potentiometer for the spot welding function and it is now very happy doing long seams without stopping so it looks like it was the potentiometer after all. At the moment I’ll run it as is but may look to find a replacement in the future or I may even just remove it and see if I can work out why it has failed in the first place.
Thanks for your help and suggestions eddie49. Your posts lead to me finding a solution.
I really like how simple these things are. It’s a replacement for my R-Tech which just went bang for some unknown reason.
Thanks for your help and suggestions eddie49. Your posts lead to me finding a solution.
I really like how simple these things are. It’s a replacement for my R-Tech which just went bang for some unknown reason.
That is good news that you have been able to solve the problem. I'm pleased that your welder is working again.
From the diagram above, the spot timer circuit is disabled by the switch being open-circuit, so it looks like the switch on the back of the pot has failed permanently "on". A new switched pot of the correct value should fix that - or you could add a separate small on/off switch for that circuit.
R-Tech are known for excellent warranty and after-sales support. Have you asked them to fix it?
From the diagram above, the spot timer circuit is disabled by the switch being open-circuit, so it looks like the switch on the back of the pot has failed permanently "on". A new switched pot of the correct value should fix that - or you could add a separate small on/off switch for that circuit.
R-Tech are known for excellent warranty and after-sales support. Have you asked them to fix it?
I'll see if I can fond some form of direct replacement pot with switch, if not then yes, that might have to be the way forwards.
I've been in touch with R-Tech about having my existing one repaired. I was just interested to see how an old transformer MIG compares to a new inverter MIG. Other than the weight, I can't seem to notice much difference. I may sell the R-Tech to a friend once it is repaired.
Thanks again for the guidance Eddie.
blockingshrimp
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Hi pal , I've the same welder but my wire speed knob wiring has come unsoldered. The wires ate numbered but I dont know which order they go into back of the knob . Any chance you could take a pic of yours please
Hello and welcome to the Forum.
The OP has not been online here for over a year.
If the diagram in Post #6 applies to your machine, the wirespeed potentiometer is connected to the PCB by three wires, marked A1 ( top ), A2 ( wiper - the centre tag on the pot ), and A3 ( bottom ). If your wires have those markings, then try connecting them in that order. The A2, wiper, centre tag, is important. The other two, A1 and A3, which I have called top and bottom, go to the left and right tags on the pot. If they are wrong, then the wire speed will simply be high in the anticlockwise position of the control knob instead of low. If this happens, then the A1 and A3 wires should be swapped over.
The OP has not been online here for over a year.
If the diagram in Post #6 applies to your machine, the wirespeed potentiometer is connected to the PCB by three wires, marked A1 ( top ), A2 ( wiper - the centre tag on the pot ), and A3 ( bottom ). If your wires have those markings, then try connecting them in that order. The A2, wiper, centre tag, is important. The other two, A1 and A3, which I have called top and bottom, go to the left and right tags on the pot. If they are wrong, then the wire speed will simply be high in the anticlockwise position of the control knob instead of low. If this happens, then the A1 and A3 wires should be swapped over.
