what format is it in ?i have a circuit diagram but i cant get the scanned image to upload?
open it then from top left depending on software choose save as then below it change format to jpgi dont know how to change the format
as you have already checked that the + to the wire feed is a good connection to the torch tip you need to check the - back to the circuit board plug, than after that according to that schematic you uploaded its a fault on the pcb
yes potentiometer would do that, you can test it with your meterive remade both the connector wires so its not that if the potentiomiter was in trouble would it give me that low volts reading i got at the motor terminals?
ok mate thanks anyway, regards,stanmanPossibly... It could go either way.
I'm going to politely step back, I'm not comfortable with my explanation skill to direct someone remotely to probe inside a machine.
if you de solder it and remove it then between the 2 outer terminals you should get a reading of whatever is printed on it ie 100k ohms then the centre connection and an outer should give smooth increase and decrease from 0 to full as you turn itwould you explain how to do that please
ok cheers snooper ill let you know how i get on, thanks for the help, stanmanif you de solder it and remove it then between the 2 outer terminals you should get a reading of whatever is printed on it ie 100k ohms then the centre connection and an outer should give smooth increase and decrease from 0 to full as you turn it
problem is the pcb schematic if for auto mig, is it the same circuit for the mono ?I was wondering that it is possible we may have skipped a few stages.
Looking at the circuit the motor does use the welding voltage via a control circuit on the PCB to vary the wire speed, but the PCB it self is still powered from the small transformer down there at the bottom of the welder.
The circuit shows a few things such as a fuse in line or a breaker?, not really clear on the main circuit. But could I suggest a check for volts on the Red circled diode on the control board. It should have 24 Volts across it and if there is then it would quickly show the small transformer/fuse etc is all OK.
The control board does seem to be the same as Snooper posted and is also the same as the circuit I posted earlier.
So here we are:
View attachment 82143
View attachment 82145
The small transformer provides AC to the board. Half wave rectified by D1 (bottom right) R10 is a 680 OHm resister provides current to the diode Z1 Zener diode at 24 Volts and smoothed by C9 a 10 uF capacitor.
The bottom half of the circuit seems to be the control for continuous welding spot and stitch welding, so if these are not working correctly could point to an issue on this side of the PCB. It looks as though T7 the BC237 has to switch on to allow the motor speed control to work.
If no 24 Volts across the diode, could you check for approx 27 volts AC across 2-6 and 5-9 of the connector.
Again just my thoughts
Adrian
ive not studied it, it could well be as simple as the selection switch needing switch cleaner, it does look like an old design and could have bad contactsThis is the board layout and seems very similar, enough to have a comparison with it.
View attachment 82146
Adrian