Help needed

[Jimbob’llfixit]

Hi did this fix work?

I have the same problem. I have taken the relay off and tested with 12v but doesn’t do anything, the resistance climbs steadily regardless of it being powered or not. Here’s some photos too.

Eddie would you mind placing an order for me please?

 

[eddie49]

Hello, and welcome to the Forum.
I have not had any feedback about whether the replacement relay works or not, but they are still on sale.
I will PM ( private message, conversation ) you an Email in Polish, to which you can add your name & address and then send on to the Polish company.

 

[prepman]

Where can I get a JQX-29F-A relay, that will just replace the one on the board?

It might be totally irrelevant to your particular problem. But I had a Draper welder with a pcb relay issues. This was the main power relay. I gave up with it and mounted a SSR on the metal work and wired it back. Still going 12yrs on.

Transformer repair

I've recently bought a 2nd hand faulty welder off eBay to repair, a Draper MW151AT. I've found that the external windings of the primary transformer are damaged. But only 2 turns. It looks as if the the set has fallen over on to it's side whilst powered up and a foreign metal body has got...

www.mig-welding.co.uk

 

[eddie49]

PM sent to @Jimbob’llfixit with suggested Email to order the relay from Poland.

 

[Jimbob’llfixit]

Eddie you’re a hero.
Email is sent, I’ll let you know how it goes

 

[kevster]

Usually the relay on the PCB is powered by a low voltage that is the rectified output of the small transformer on that board, routed to the relay coil via the torch trigger switch. The contacts on the relay feed AC mains to the main welding transformer. The rectified welding power is "tapped-off" to also run the wirefeed motor, via the speed controller components on the board.

In your case, the relay clicks, so that part of the circuit works. Relay contacts can burn, but the new relay should have precluded that. Are you getting the main DC welding voltage output? You should be able to strike an arc with the tip of the MIG wire ( even if it will not feed ). The tip voltage ( negative for a "no gas" welder ) should be about 15 to 30 volts with respect to the workpiece clamp and return lead. This will vary depending on the setting of the power switch(es). Sometimes these switches break or burn internally, so it is worth operating them on & off a few times, and also testing for the arc and the wirefeed fault at all settings of the switches.

Hi , could you send a diagram of how to put the switch wires as I'm being a bit thick sorry

 

[bourbon]

@eddie49. A true example of what a great forum membership we have here.

 

[kevster]

Hi Eddie

As Hutcho said, the JQX-29 relays are known to be weak and they often fail - but replacements are hard to find.
This relay switches the AC mains Live feed through to the primary of the main welding transformer. You could determine whether yours is actually faulty by bypassing it:

Connect two short pieces of mains-capable insulated wire to the right-most two push-on spade tags on the printed circuit board ( CN3 and CN4 in your second photo ). You could use piggy-back spade tag connectors, with the existing wires still in place, or solder the two wires onto the tracks underneath. In this case, in your first photo, these would be the left-most upper two solder pads.
Join the other ends of these two wires to a mains-rated On/Off switch ( e.g. a 1-gang 1-way rocker lightswitch ).
** This switch and the wires will be at 230v mains potential !!
Plug in and power up the welder. Operate the extra switch. The main welding transformer should power up.
Then press the MIG torch trigger switch. The smaller relay should click, the wirefeed should start, and you should be able to weld. If this bypass test is successful, it means the JQX relay is defective and needs to be replaced.

Could you kindly do a diagram of the wiring to add a switch as my relay is done for and I would love keto bypass it until I get a new relay. Cheers

 

[eddie49]

Hi Eddie
Could you kindly do a diagram of the wiring to add a switch as my relay is done for and I would love to bypass it until I get a new relay. Cheers

Hello and welcome to the Forum.

Could you please clarify what you need:
- what make and model of welder do you have?
- what is the fault?
- does it use one of these JQX-29 relays?
- have you already confirmed that the relay is faulty?
The procedure I wrote in Post #6 of this old thread was intended to prove that only the large relay was at fault, and the rest of the welder was OK. If the relay is bypassed in that way, the welder will be on all the time, and the torch tip will be "live".

If you do need a JQX-29 relay, this thread:

rockworth ar 120 mig welder help

hi i was selding today with a rockworth ar 120 mig welder when the feed just stopped then i pull triger i can here it clicking inside i checked the feed moter with a 9v battery and it moving i check the 2 fuses on the pcb there ok can anyone help

www.mig-welding.co.uk

states that an original one can now be ordered from AliExpress, rather than the relay-and-daughterboard version from Poland.