MIG Welder Not Working

[timswait]

My Clarke 150TE Turbo MIG welder has just stopped working. The fan runs and the mains light in the switch comes on when you turn it on, but when you press the button on the torch there is no wire feed and no arc . Any ideas on whats up with it or what to check. I'm fairly competent with electrics and understand the principle behind how a welder works, but I've taken the side off and it's a bit hard to trace where a fault might be. It happened immediately after changing the roll of wire if that's significant, ie was working before and not after!

Cheers
Tim

 

[weldequip]

It's the Thermal Overload Switch that has kicked in. When the light on the ON/OFF switch goes out it will start running again.
weldequip

 

[timswait]

I don't think that's it. The light in the on/off switch is always on when the welder's on, it's just a mains power light. Also i've given it a couple of since it stopped to cool down, I though it might be thermal cut out too, but the transformer and everything else inside is stone cold now. Does it need manual resetting or is it automatic?

 

[weldequip]

Hang on a minute, I'm confusing myself here! I've been selling the things for nearly 20 years & yes, you are right, the ON/OFF on the Clarke comes on striaght away. It's on some Sealey/Telwin machines were it only lights up when the thermal protector kicks in.
They are automatic, self-resetting devices yes.
I'm afraid it sounds like you have a more serious problem - probably the PCB.
You can test the motor on a 12v car battery but it does sound like the main board; not a problem associated with Clarke in particular, but ALL MIG's eventually.
weldequip

 

[timswait]

How much are the boards and where can I get one? The board doesn't really look very complicated. There's a fairly chunky relay on it which I guess turns on the motor and transformer when you press the button to start welding. It doesn't click when I press the button, so I guess that's a good place to start? Other than that the board seems to be mostly concerned with motor speed control, and since there's no arc either I guess the problem probably doesn't lie in that bit?

 

[weldequip]

The boards are not complex on that machine no, but try & make one!!
They will be around £45-£50ish I would expect. The problem with Clarke (and most others) is that there is a MULTITUDE of different boards for the same model; designed to keep you, the consumer confused & us dealers likewise!
There will be a number on the backside of the board, E...something. That number will denote the year of build & price/availabilty.
weldequip

 

[timswait]

Just found the problem (or at least another symptom!) There's a miniture 500mA fuse on the board which has blown. I'll get another from Maplins tomorrow and see if it cures it. Fingers crossed there's no other problems which caused the fuse to blow in the first place.
Thanks for your help.

 

[weldequip]

Usually another porblem that causes a fuse to blow but with it being only milli-amps hopefully you will have got away with nothing.
weldequip

 

[timswait]

No luck
Put a new fuse on and it blew as soon as I turned the mains on. Tried another new fuse and this one hasn't blown but it's still not working How much is a new board. It has E [diameter symbol] 795A written on it.
Tim

 

[weldequip]

Hi Tim,
We MAY just have one in stock, I'll check at work tomorrow morning for you; if not I'll get a price for you.
weldequip