syncrowave stopped welding - any hints?

[Disco_Mark]

Very recently I bought a Miller syncrowave 300. It is the basic machine, with no optional extras. It does have a cooler, and a foot pedal.

Before today, I had very briefly run it up to check that it strikes an arc, although without the water cooler on, or with any fluid in it. It did this successfully, and I did a very short test bead with it (less than 1")

Today, having connected and filled the cooler up, lifted it off the pallet it arrived on, onto the trolley I made, I tried to start teaching myself to tig...

However, it will not strike an arc. I can get absolutely no welding current from the machine whatsoever.

The HF seems to be working, and the earth is good. on AC the, with the HF set to continuous, there is plenty of HF, but not weld current. on DC and HF Start there is nothing. Even touching the electrode to the work does not illicit a spark.

The gas solenoid is is being triggered, and gas is flowing at the appropriate times.

Both the Pedal and the torch have the same effect.

Given that I had the machine working about a week or so ago, and all that has changed is it's physical position, and that the watercooler is filled up connected, can anyone suggest what else might have caused the complete lack of welding current?

The troubleshooting section on the manual suggests that if the machine appears to be operational, but there is no weld current, then the 110V supply and control breaker may have tripped. The breaker does not appear to have tripped out, and the water cooler (powered from said 110V supply) is still happily pumping water around. I have attempted to reset the breaker - but it doesn't seem to have tripped. That is as much help as the manual has been so far... although the next step is to start working through the circuit diagram.

As said, if anyone happens to know anything helpful about the machine, I really would appreciate any help.

Thanks
Mark

 

[Jake SS]

Assuming you have checked simple things.
With HF off. Check for open circuit voltage, switches, meter for 110v, meter breaker, check that relays are operating, check PCB connections, something may have come adrift during move.


Cheers

 

[^neo^]

Has it got a 'stick weld' switch?
Try it on this (presuming you have a rod holder and some rods!) and see if it welds.
Sounds like the main contactor isn't kicking in

 

[Disco_Mark]

No stick weld switch as such, but the stick settings are pretty much turn everything 'tiggy' off and go from there. I did do a little experiment and tried turning everything off and then each one back on in turn to see if anything happened, and nothing did.

I suspect you are right about the main contactor not kicking in - the circuit diagram shows two in parallel, so it seems odd that they both stop working. will investigate both the contactors and the control for them...

I checked inside for anything obviously loose, and nothing was, so I shall do a more thorough check with the meter today.

cheers
Mark

 

[malcolm]

I also have a Syncrowave that's unwell, so would be interested in what you find. Mine has trouble with some of the settings. I'd set it to DC, current to panel, turn HF off and measure OCV between the torch and earth for a starting point. If you are lucky and get a little you might be looking for bad connections. If you are lucky and get none then that might be easier to trace with continuity.

 

[^neo^]

Go right through it removing the relays one by one, clean up the terminals and visually check them. There's not too much more you can do unless you have a mutli meter, wiring diagram and some sort of clue how it works.

 

[Disco_Mark]

Go right through it removing the relays one by one, clean up the terminals and visually check them. There's not too much more you can do unless you have a mutli meter, wiring diagram and some sort of clue how it works.

Well, I do have all of the above - a multi-meter, a circuit diagram and after studying the latter for some time, a degree of understanding of how it works, and yet I am not really any closer to working out what's broken...

There are only 2 relay like devices and one of them is for the gas valve, and is working fine.

The other one is not operating, but I cannot identify if it is involved in welding current control.

I also have a Syncrowave that's unwell, so would be interested in what you find. Mine has trouble with some of the settings. I'd set it to DC, current to panel, turn HF off and measure OCV between the torch and earth for a starting point. If you are lucky and get a little you might be looking for bad connections. If you are lucky and get none then that might be easier to trace with continuity.

In the setup described, I got 0V OCV. nothing at all.

I have traced continuity back from the tip of the torch, through the switchgear to the rectifier. I have cleaned the terminals on the switchgear too - one was looking a little crusty but all were conducting.

The only thing that is not happening is that there is no welding current flowing when the button on the torch is pressed.

This means I suspect a dry joint or dodgy component somewhere on the control circuit board or a break somewhere in the wiring possibly...or possibly something else....

suggestions still appreciated.
Cheers
Mark

 

[Jake SS]

Did you try taking the plugs off the PCB and pulling PCB out and check all joints, pins, sockets. Then plug it back in and try again.
TRY THIS FIRST

If you only have an owners manual let me know the serial number and I will see if I have a tech manual for your machine. Which would make it easier rather than walk you through it.

Cheers

 

[Disco_Mark]

Jake,

I visually checked the PCB of the main circuit board for blown components, but I will remove it and clean the connections to the machine, and see if that works.

a tech manual would be very much appreciated. The manual I have is as downloaded from the miller site, as the generic manual for the syncrowave 300. The website didn't recognise the number I have for it. The machine is also badged 'Interlas' as well as miller, if that makes any difference.

I'll pm you my email address and the serial number.

Thanks
Mark

 

[Disco_Mark]

Had another go a the machine last night, and have confirmed that it is getting 415V - it had been suggested that the cause may have been a dropped phase, but no.

I also pulled the main circuit board out and inspected and cleaned the multiway connector on the edge - it was actually fairly clean, but it couldn't hurt. All connections to it looked and felt secure.

and yet it still doesn't work

I have been trying to get some more information on the machine, but no-one recognises the serial number. here is a picture off the back of the machine if anyone could shed some light on it:

Cheers
Mark

 

[astro_al]

Can't see any pic, Mark?

Al.

 

[Disco_Mark]

Hmmm... it's showing for me, and it's hosted on here. I'll try attaching it...

Please excuse it's undressed state - I have been probing inside extensivly...

 

[Jake SS]

Did not find any info on that serial number but have emailed you a manual that should help.

Cheers

 

[Disco_Mark]

Thanks for your efforts Jake. The manual suggests a couple of other places to check that I have yet to try, so I see if I can get anywhere with it tonight.

Thanks
Mark

 

[smp]

Couple of things you can check :- there is a switch for MMA/Stick, it is the
"Contactor local/remote" switch, top left, local is mma, remote is triggered by
the torch switch, turn HF off and put into local, check for OCV, 70 volts ish.

Try moving the "Polarity Straight/Reverse" and "Range High/Low" switches up and down a few times, the blades on those switches can get dirty and give a bad contact.

There is no Contactor in that machine as such, the main pcb fires the Thyristors to get OCV when it recieves on signal from switch in Local or trigger pressed, this signal goes into an Optocoupler which in turn starts firing pulses to the Thyristors. Very common for that Optocoupler to fail. Shows as HF on, Gas on but no OCV.

 

[Disco_Mark]

smp, that sounds like exactly the problem.

Tested as you mention - set to local, and HF turned off, the OCV is 0V.

Switched have been moved around, and in some cases the terminals/wipers have been cleaned up with little light emery cloth action... still nothing.

It sounds a lot like either the Optocoupler has failed, as you suggest, or the Thyristors are not being fired.

Could I be really cheeky, and ask you to let me know where the optocouplers are on the circuit diagram I posted earlier... and is there a way to bench test them?

Thanks very much for your help.
Mark