Migmate 105 wire feed motor wont turn

[Melvyn Dodridge]

Pressing the torch trigger and no wire feed. Done lots of checks. The earthing is good. Had the PCB off, the relay coil is 200 ohm, the grey box transformer is 30 ohm, the transistor TIP35 is blown, the BE junction is open circuit both directions. The resistance between the BE terminals is about 430 ohm (transistor out )
The bad news is I have replaced the transistor and there is still no volts across the motor, the motor is not open circuit.
Any clues on where to go from here, apart from binning the welder!

 

[the snooper]

is there a dc voltage across the torch and earth (trigger pulled), the motor is powered from the welding transformer worth testing the welding rectifier to make sure the motor would be receiving dc

 

[rtbcomp]

Welcome to the forum - I've moved this to a more appropriate section.

 

[Melvyn Dodridge]

Checked the PCB grey transformer and it is open circuit on the mains side. Can you get these 230/12V 1.5 VA with make like a reverse RJ on it

 

[rtbcomp]

Any transformer matching the input voltage & output volts & amps will do, you may be able to scrounge one from a scrap plug-in power supply.

 

[Melvyn Dodridge]

Sourced the exact transformer from RS components, fitted it today and now have a working welder
Total cost with transistor about a fiver so well pleased. Not sure why the fault so hope will not repeat

 

[Robotstar5]

Thanks for letting us know.