Rubber gloves wellies and a healthy dose of panic helps keep my fingers away from anything that could give me a hair raising moment doesn't stop the worry that I'm gona fry something on the PCB though.
If the relay is the big switch for the contactor and the gas etc would the signal from the trigger be the thing that gets the relay to operate? Looking at the PCB this could be possible!
If so then the voltage that goes through the trigger that could be the problem?
If this is correct (big if) then if I jump 24v to the trigger it would hopefully operate the relay etc.
Now the crux should I jump 24vac or dc and if it's dc do I go 24vdc or 0vdc
What's the risk to the PCB, the welder and me if I use the wrong Jump?
I would think that the 24vdc would be switch by the torch trigger and that would control the relay on the PCB (relay should have coil voltage printed on top). And the relay will switch the coil voltage to as solenoid and coil on contactor
I have only briefly skimmed through this, and I do not want to teach anyone to suck eggs by any means, but have you checked continuity on the wires going to and from the torch switch?
I know it may sound daft, and may be completely fine, but after spending 9 hours on a job fault finding only to find out the problem was a broken wire has made me very weary of dodgy cables.
if you have already checked it and I missed the bit where you said 'I have continuity on the switch wires' then I appologise
No worries, about making sure the logic has been checked through. Ibelled through the Torch trigger using the multimeter on audible resistance setting.
No bell until trigger pulled.
Checked agian at the wiring between the europlug and the PCB. Seems ok.
Going to see about a manual/circuit diagram before I try anything else.
Those Numbers on cables will help no end to follow the circuit, you could try manual relay operation.
There should be volts on one switch lead would be surprised if AC.
Yes the numbers on the wires are great (especially when your colour blind LOL) I can follow the wires and in the majority of cases understand what's happening at the ends. I'm creating a list of wire numbers and what each end connects to. I may then do the PCB as well if I cannot get a diagram, dont have any idea where to start though.
I'm not getting any voltage to the torch to switch. The 2 wires to the torch go to the PCB. No voltage at this end of the wire either. So I think there's an issue on the PCB.
Checking online the PCB relay (modern equivalent of it) the coil is 24vdc. The Semikron Rectifier appears to be getting 24vac and then putting 24vdc onto the PCB, again pointing towards the PCB.
If there were parts available at a reasonable cost I'd replace the PCB but due to it's age.....
My other option seems to be to get the main components on the PCB (or at least modern equivalents) and work my way through swapping 1 item at a time.
Continuity checked the tracks on the PCB, all bell out ok.
Resistance checked the Resistors, and yes I get resistance on all of them, whether they match the colour codes??? (being colour blind can be a pain, the missus helps but 'what colours this' gets a bit repetitive)
I'd hate to scrap this as it worked well and put some good work in on repairing car bodies, which is why I dug it out of the shed. I'm trying to get ready to repair an old Jag XJC.
I'm going to try the MIH company again tomorrow. A local company were polite about not being interested.
http://www.thomasproctor.co.uk/
Dave Byers was the man to speak with-- thats a while back, best to call round if possible, Dave was in the very far end, Not the sales consumables end. Sort of "Birtley" end, not "Newcastle" end
Hi. I have repaired quite a few of these PCB`s in the past. from what you describe and previous repairs on these PCB`s it does sound like it is the PCB that is faulty. Faults vary on the PCB from the power supply failing to the I.C or a transistor failing, all which can give the same sympton of the machine not triggering. Please PM me if you would like me to test / repair the PCB.
This lad might be cheaper than Proctors, but no harm in calling in, there might well be a woman in the office on the left inside the big doors into the warehouse, Daves workshop was attached to the office.
I`m presuming he is still there. lived down Blyth area.
Or Ring him
MIH have a circuit diagram/parts list for this model and also a user manual but for the 180. Both copied from the original and posted for very reasonable price.
I'll get these and then do some more checks to confirm what I already suspect.
Just out of interest. This model has 2 additional options via a 3-way rocker of being able to stitch weld (has a separate timer) and spot weld. These are obviously controlled via the PCB. I only ever use the continuous weld. So If the PCB replacement/repair is not cost effective how difficult to remove the PCB and wire the components direct!? Note! the Wire feed has a separate controller. I've seen some stuff on this forum and elsewhere, where some people have built a mig welder.
MIH turned up trumps Manuals turned up, lots of head scratching ensued Some conversations with the Electrician at work lead to a systematic approach to tracking down where I lost the trigger signal.
On the PCB there are 2 timers. At this time it looks like at least 1 of these may be faulty. Bypassing it briefly got the welder functioning correctly. It was brief as I managed to touch 2 terminals on the Timer and blew it I've found replacements at RS (The ones on the board had a barely visible RS logo and the part number ) The cost from RS is an eye watering 74p each. I'll need a better soldering iron to get in for the replacement as the terminals an solder areas are close together and small.