Went to use my old Sealey MightyMIG 100 today, it gave out a bit of a course buzz from the transformer, then popped a 13amp fuse. Nothing obvious when I looked inside. Went through loads more fuses trying various scenarios, each time it gives a course buzz for a couple of seconds before popping the fuse, but can’t seem to find the fault, unless the transformer is f**ked !

Is it time for a new MIG ?, if so, which one ?

If its been outside through the cold spell it may just be a build up of condensation. Try leaving it somewhere warm over night to dry out and try it again in the morning.

Sounds like the windings may have developed a short 👿

Has been in the garage for years, will take it indoors tonight and try again. Cheers for the tip dropoff.

I’d be amazed if condensation caused a curable short like that – I’d have thought that if the coils were breached by an arc through the moisture you’re probably looking at a permanent short now. Water isn’t THAT conductive.

If you’ve been using it lots you might find you overheated the transformer – did you check out the duty cycle rating on it? Some are rated at quite low current in constant use.

coffeeking, never got a chance to overheat it, fuse popped before I got a chance 😥

Any good deals on MIG’s about, got one day left before the VAT rise !

machinemart are having a sale?
have you tried openin hte cover, disconnecting the power cable and checking it’s not a short in the cable feeding the transformer? Measure the resistance of the coil primary while you’re at it?

Sounds like something arcing. Take the cover of, and check for anything obvious wrong.