MIG welder fault
 

I've just got an old Cebora 160A MIG welder which was cheap and doesn't work. The cooling fan runs but nowt else.

Looking inside at the transformer, there doesn't appear to by any signs of excess heat. The wire feed motor, contactor and gas valve appear to be all controlled by a small PCB with the wire speed control pot, a couple of 10A relays, a BU348 transistor and a 74HC14.

Does anyone know about old MIG welders? My last one was a small SIP and I remember having to repair the motor control several times during it's life. A circuit for this would be handy, otherwise I'll be drawing one.

Re: MIG welder fault
 

I can remember a while back snap-on put their stamp on some of the smaller cebora stuff, ive just googled cebora and snap on has come up on mig welding forums etc. You may get a schematic from snap-on.
regards poppydog

Re: MIG welder fault
 

Check for supply from transformer. Some migs have separate transformers for control electronics and arc supply. Check continuity on wiring to trigger. If possible try pressing main contactor in manually whilst attempting to get it to arc up on a piece. Lastly check general wiring condition and check rectifier diodes as these can burn out. Cebora migs are generally pretty robust and if you scout about on net you should be able to find a wiring/service manual.

Hope this is of help

Re: MIG welder fault
 

This is probably no help but I used a Cebora 130 badged Snap-On and on those the one weakness is the contacts in the torch. (readily available Cebora parts on you know where)

I assume the 160 has a proper euro torch? (plugs in to the front of the unit) and if it does this, being something which takes a lot of abuse, may well still be an the problem. The easiest way to check a euro torch is to borrow one from a working welder if you know someone with a suitable mig. Euro torch assemblies should be interchangeable regardless of manufacturer.

Re: MIG welder fault
 

There's not a lot to go wrong with a basic MIG welder. The very basic 'live torch' types have only one transformer, switched on all the time, and the torch trigger just starts the motor drive and releases the gas mechanically, but it sounds like yours is more sophisticated.

If it's anything like my 'Portamig' unit, there will be a separate control transformer to power the wire feed motor, fan and main relay. This is presumably working if the fan is running, which is a good sign. The contact in the torch trigger should make a circuit which switches on the gas valve, the wire feed motor and the relay which switches the primary of the main transformer. It sounds like none of these are happening, so check the switch in the torch, and its wiring, first. They have a pretty tough life and the cables get damaged.

Chris

Re: MIG welder fault
 

Thank you to all, I checked the welder this morning and it’s only the wires in the torch that are broken. Shorting out at the inboard connector gets the machine functioning properly. A new torch is next on the purchase list.

I’m a happy man!