- Thread starter Harry m
- Start date
I believe that this is the circuit diagram for the Cebora 160:
https://www.cebora.it/manuali/fuori_produzione/850-852/sch_850-852.pdf
Does the data plate on your machine show the same model number - 850 ?
That diagram shows the auxiliary power supply comes from a 24v AC transformer. This is probably rectified to DC on the PCB, but there isn't any detail of the PCB internals. The gas solenoid is shown as being in parallel with the operating coil of the main Contactor. The coil voltage and AC or DC specification should be written on the gas solenoid or the Contactor - and a voltmeter would confirm.
On the other hand, the component that supplies the power to the solenoid ( relay or Triac ) may have shorted. Again, a voltmeter or pulling off one wire would prove this. Finally, try clouting the solenoid with a BFH.
https://www.cebora.it/manuali/fuori_produzione/850-852/sch_850-852.pdf
Does the data plate on your machine show the same model number - 850 ?
That diagram shows the auxiliary power supply comes from a 24v AC transformer. This is probably rectified to DC on the PCB, but there isn't any detail of the PCB internals. The gas solenoid is shown as being in parallel with the operating coil of the main Contactor. The coil voltage and AC or DC specification should be written on the gas solenoid or the Contactor - and a voltmeter would confirm.
On the other hand, the component that supplies the power to the solenoid ( relay or Triac ) may have shorted. Again, a voltmeter or pulling off one wire would prove this. Finally, try clouting the solenoid with a BFH.
Harry m
Member
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- Yorkshire
The solenoid does not seem to be the problem it has Permanent 230v feed so I’m thinking I must have a relay that has failed in closed position if anyone knows where to find it, it would be of help to me I suspect it will be on the circuit board. I’m thinking that I could add a relay to switch on the gas from the wire feed motor what do you think, but before that I would like to try and sort it. A bit more info on the welder it’s a Mercury 160 about 15 years old.
Some earlier threads imply that the gas solenoid being permanently on is a common problem on the Cebora Mercury 160:
https://www.mig-welding.co.uk/forum/threads/welder-problems.33766/
https://www.mig-welding.co.uk/forum/threads/help-problem-with-my-mig.25139/
The second thread states that the relay has a white plastic lid, so you can't see if the contacts have stuck. However, it should be possible to find the correct pins so that you can check with an ohmmeter if the contacts are always closed ( with the machine unplugged ). Alternately, maybe you could carefully prise the plastic case open.
From the diagram I linked to above ( perhaps not the correct one... ), the gas solenoid is controlled by a relay but the solenoid is also in parallel with the coil of the main Contactor. As well as the gas solenoid, is the main welding power always on?
https://www.mig-welding.co.uk/forum/threads/welder-problems.33766/
https://www.mig-welding.co.uk/forum/threads/help-problem-with-my-mig.25139/
The second thread states that the relay has a white plastic lid, so you can't see if the contacts have stuck. However, it should be possible to find the correct pins so that you can check with an ohmmeter if the contacts are always closed ( with the machine unplugged ). Alternately, maybe you could carefully prise the plastic case open.
From the diagram I linked to above ( perhaps not the correct one... ), the gas solenoid is controlled by a relay but the solenoid is also in parallel with the coil of the main Contactor. As well as the gas solenoid, is the main welding power always on?
New member here from the US. I just picked up a Marquette 155 220 volt MIG welder which is made by Cebora. I'm having the issues of the gas solenoid being on whenever the machine is switched on, and the wire being hot all of the time. I suspect it's the relay on my welder also, which looks like the 45 series Finder described above. Is there a particular model number of Finder 45 you picked up? Also, the LED for the power light is not working, does anyone know what the specifications might be for that so I can replace it also when I pull the board to do the relay? Thanks in advance!
Harry m
Member
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- Location
- Yorkshire
https://uk.rs-online.com/web/p/non-latching-relays/4946360/ Link to the one I got 16amp 24v power relay
Thank you sir, I was able to confirm that the relay in mine was also 24 volt and it was marked 16 amp, so the one you listed is perfect. I have two on order now, $6.28 plus shipping US each. Beats paying $160 to have someone look at the circuit board.....
I'm not an electronics guru, so I took it to a shop to be repaired this morning. Got a call this afternoon it was finished, so I'll try to get it put back together probably Wednesday morning (work afternoons). Crossing my fingers hoping that it's the total fix, I know it was bad but since my power LED wasn't working either, I'm sweating the transformer. Unless they tell me they found a cold solder joint on the LED, that would make my day. Read some posts the the power LED runs off of the transformer on the PC board, my trigger on the gun works to activate the wire feed but I also wonder if the wire feed isn't fed off of a separate drop from the main transformer of the welder itself. I guess I'll find out shortly. Thanks again and I'll report back!
Well, fix one thing to find another bad. I installed the circuit board with the new relay, and had nothing. Fan runs, but no power LED (it didn't work before, and I was hoping it wasn't the transformer) and no wire feed or gas solenoid. Apparently with the stuck relay the 24 volts from the main that power the wire feed were back feeding and allowed the torch trigger to work. Now that the relay is fixed, no 24 volts. I talked to the guy who did the relay install for me and he walked me through testing the transformer, and sure enough the primary was open. So I have two on order (might as well have a spare, right?) but they're coming from your side of the pond, so I'm on hold until they get here. Again I'm not an electronics guru by any means, but someone had wired this welder up to run off of 110 volts. My electronics guy who installed the relay and who helped me troubleshoot the transformer said that could be the source of most of my problems, 220 volt electronics don't like 110 volts. So, once the transformer arrives I'll give it another shot. Again, I'll report back, I want this thing up and running!
That's an interesting sequence of faults. Normally the small, potted, plastic-encapsulated transformer on the PCB runs the small relay. The contacts on that relay close and power-up the main welding transformer, either directly or via a large Contactor ( and also the gas solenoid ). It is then a tap off the main welding power that runs the wirefeed motor, via it's speed controller. In the case that the contacts on the small relay have welded themselves shut, all this comes on as soon as power is applied to the machine. However, if the faulty relay is replaced, you then do need the small transformer output to provide that initial control, and these tiny transformers do seem to fail quite often.
Congratulations on sticking with it, and good luck for the complete solution!
Congratulations on sticking with it, and good luck for the complete solution!
Exactly. Everything on the machine went live when it was switched on. The gas solenoid was open, wire was hot, and the torch trigger activated the wire feed like it should. Reading other posts on here though I found one that said that if the power LED didn't work to suspect the transformer. Mine never worked, but I was hoping that it was just a cold joint or something.
Once the bad relay was replaced that tap from the main wasn't active anymore, so no power backfed to the gun trigger. The new transformer should fix it.... just waiting for it to arrive.
Once the bad relay was replaced that tap from the main wasn't active anymore, so no power backfed to the gun trigger. The new transformer should fix it.... just waiting for it to arrive.
Final report, it's alive! I'm not sure how much current the transformer needs to be able to handle, but the big issue was physical size on mine. I was not able to even use a 3 va transformer because it wouldn't fit on the board, it was a tight fit with the other components there. Ended up with an almost perfect fit using a transformer with dual outputs that my guy paralleled to give 2.3 VA. So far it's working fine, if anyone needs the part number here is a link to RS which it seems like most of you use https://americas.rsdelivers.com/pro..._alWln3IGjZ3e49md362ioGW1a3L4iWhoCnOwQAvD_BwE
