trouble-shooting SIP Migmate 100

[foy9999]

Hi there

I have a the above welder (per title) and it works well for me but in last few days I've been having problems with it and not can't get it to work at all.

I opened the case to check for obvious problems like burnt or disconnected wires but couldn't find anything obviously wrong.

Years ago someone fixed it with a by replacing a small component that had went black or something. I can't remember exactly.

There is a sort of circuit-board in there and again that looks fine apart from I can see some blackness inside the clear plastic cover over one of the components.

Anyone know what this does and/or if it could be the cause of my problem.

I see it is soldered to the board so it's unlikely the guy the last time replaced just this. Perhaps he replaced the whole board.

I see on Ebay there is a service where you send them your board and they fix it for around £40

Has anyone used this service?

thing from inside the welder

ID

thinking the smoked-out component is to blame

 

[johnrev]

The most common faults on boards like this seems to be the small transformer (the black square lump) or the relay (the thing with the plastic cover). If you have a multimeter you can check these by testing the voltage at certain points. Best person to help is @eddie49 but basically the transformer should be getting 240volts at two of it's pins on the underside of the board. It's mains voltage and it hurts so be careful. The other two pins should give a lower voltage as shown on the transformer of 12v. Both these will be AC volts so you need the AC volt range selected on your meter. This low voltage is fed to the round thing RCT1 which is a bridge rectifier and converts the AC to DC volts. It will be a bit higher than 12v but nothing hurty.
The relay has this low DC voltage fed to two of it's pins when you pull the torch trigger and switches power to the wire feed etc. via two of the other pins.
All this is easily tested with a meter and will give you a yes or no as to whether these parts are working as they should. Anything more complicated will need @eddie49 to take you through a repair but nothing is too complicated on these boards so it is starightforward to get it working for very little money.

Take care because as said there is mains voltage flying about on the board so wedge it somewhere safe while you test it with the machine switched on.

John