Ifa 185 smart mig

[Garyj88]

Ive tested the 6 diodes there all reading .471 and 0 on the reversal!

So frustrating tryinf to find out the problems

 

[rtbcomp]

Does the relay buzz if you power it up without the rectifiers in? Haven't a clue what that would mean - just clutching at straws!

Does the relay and its wiring appear to be part of the original unit or has it maybe been added later as a modification?

 

[anjum]

Is the coil voltage on the finder 65.31 the same as the one you took out. Sometimes there's quite a few variants of the same relay number. Don't know why finder do this. It's even worse when the relay coil isn't marked as one of the ones in my Clarke plasma king 35 which I'm trying to fault find at the moment.

 

[Garyj88]

I can post a pic of the two relays but im sure its correct im the waiting on a new one again to try in without rectifier to see if it still buzzes

 

[Garyj88]

Ok so I have tried without recifier and it still buzzes! There is six wires going to the control at front of welder from main transformer for setting power I disconnected number one setting wire and relay stops buzzing

Any suggestions

 

[rtbcomp]

I can't help thinking someone has been tinkering and it stopped working after that. I'm really stuck without a wiring diagram.

 

[Garyj88]

Is there anyone on the forum could help us out! One hundred percent it was defintely working and stop it lay about then

 

[migmug]

Looks like an Autoplus 171, found the diagram on

http://www.sipuk.co.uk/sip-spare-parts/

 

[rtbcomp]

Thanks for that MigMug - I've added the link to our Links section.

Assuming it's the "12v Relay" in the diagram that's the culprit, it is driven from the PCB, but I was under the impression that the fault ocurred with the PCB disconnected???

Looking at the photos the welder has a spot timer on it, its job is to switch the relay on and off at timed intervals, if this circuit has failed then we'd get the symptoms we're getting.

Assuming the fault occurs with the PCB connected

1) does operating the timer control make a difference?
2) are there any burnt tracks or components on the PCB?

To test the unit without frying the relay it may be possible to connect a small bulb or an LED in its place.

 

[Garyj88]

Hi many thanks for your response.

I disconnected the pcb completely tonight and the relay still buzzes!

I checked the spot relay timer and moved it between position but this has no impact on relay

I will attached picture of back of pcb and front

wat size of bulb should I use?

 

[rtbcomp]

If it still buzzes with the PCB out then the fault's somewhere else, both wires to the coil go straight to the PCB.

Have a close look at the connectors on the wires that go to the PCB, There may be a bit of metal shorting a couple of contacts out.

Can you trace the coil wires back to the PCB?

 

[Garyj88]

Ok I have connected a bulb and put torch on and troed to peform a weld its giving of small blue sparks as if it is trying to weld.

I have traced wires from pcv and the connectors and wires all look ok