Hobart Welding Tools - Page 8 - Recent Questions, Troubleshooting & Support

Check internal connections, Check to see if CR3- a heavy 24 volt contactor- closes. And check for continuity of secondary winding of transformer which connect to the rectifiers. The rectifiers are likely dead, or contactor has failed- either the coil winding or the contacts. Bypassing therectifiers will allow machine to work as an AC weldert, but your results may be unpredictable.Also check for continuity between pins 1 and 4 on heat selector switch (primary windings in series, you should see some resistance, but not a great deal).

There are two wires comming from the circuit board to the wire feed motor. You can try running the motor directly from a 12v battery or two for 24 volts. You might want to look at the name plate on the motor to check the normal DC current it draws. If you do not have an ammeter, you could use a fuse close to or just under the normal current. If it runs and draws too much current, then you know you have motor problems.If it runs well and draws a fraction of normal current,you know the motor is good. Before you condem the circuit board, check that it is receiving the correct input voltage. If the welder is dual voltage,then somebodys mistake making voltage change could send 240 v to the board that is meant to receive 120v. Hope this helps, Robert

make sure rollers are clean and slots not wore out check alignment
do not over tighten wire feed so it smashes the wire
flux wire is hard to get a good setting
make sure if you can set it for gas welding it is not on this setting

A schematic would certainly help, give Hobart a call and ask for a wiring diagram. or manual. Hobart are very helpful and may even give you guidance, you may have to pay the postage, they usually fax these documents so it will not cost you anything.

Does it just do it once for a short time each time the machine is plugged in? If so, don't worry about it.

lp

Have you checked the trigger inside the gun to make sure it is not stuck?

have you went to your local welding store? Praxair or airgas can call Hobart for the part you request,or they will call their Hobart salesman for you.