Old Cebora PCB

[Multiwelder]

Hi
I'm new here and already need help.
My old Cebora 170 has been having PCB problems.I had it repaired twice but it still comes back faulty.The problem is that they're not available new any more.
I've been thinking,these are fairly simple machines,couldn't I fit a DC motor speed control, a couple of relays for the contactor and gas solenoid valve just to get the thing going?
I believe the motor is 27v DC and the contactor is 230V.The Gas solenoid valve is 27V ac.It seems a shame to throw the welder away although my new inverter machine is a gem!
My knowledge of electronics is zero by the way.

Thanks in advance.

 

[the snooper]

What features does the main have ? What is the fault and post a pic of the pcb

 

[500e]

http://www.cebora.it/manuali/fuori_produzione/840/sch_840.pdf
Could be the one
If not try hunting here
http://www.cebora.it/articoli_fuori_produzione_uk.html

 

[Multiwelder]

Yes you could do that. You'll lose any extras (spot timer etc.) but it'd work as a basic mig.

You should find a small transformer in there for the feed motor and solenoid, and it may operate the contactor too.

The spot timer was never used anyway so I wouldn't miss it. The secondary transformer gives out 27V and 380V. The Contactor appears to be 230V but I can fit another,they're not expensive.24V relays should work I imagine.

 

[Multiwelder]

What features does the main have ? What is the fault and post a pic of the pcb

By features what exactly do you mean? It's a simple thing.It has a spot timer,never used, and a rotary switch with 6 positions. Wire speed is controlled by a knob on the PCB which still works actually so I could probably leave that in.

 

[Multiwelder]

http://www.cebora.it/manuali/fuori_produzione/840/sch_840.pdf
Could be the one
If not try hunting here
http://www.cebora.it/articoli_fuori_produzione_uk.html

Thanks,I found that already.

 

[Multiwelder]

Yes you could do that. You'll lose any extras (spot timer etc.) but it'd work as a basic mig.

You should find a small transformer in there for the feed motor and solenoid, and it may operate the contactor too.

Thought I'd replied to your post but can't find it. I could leave the PCB in place because it's still powering and controlling the wire feed motor and install two separate relays for the contactor and gas valve. Would this be feasible?

 

[the snooper]

So what's the actual fault you are experiencing?

beat me to it

 

[Multiwelder]

So what's the actual fault you are experiencing?

Presently it only controls the wire feed motor.When I first installed it this morning if I left the machine on for 20 mns or so the contactor would work albeit with a lot of chattering and arcing and the gas solenoid valve would also work.I managed to weld a bit after the contactor stabilized but everytime I switched the machine off the whole process started again.

 

[the snooper]

get a good magnifying glass and start looking for dry joints, especially where things get warm when powered on

 

[Multiwelder]

get a good magnifying glass and start looking for dry joints, especially where things get warm when powered on

Will do.Never too late to learn electronics.