Sync 250 issue - KA755791

[tbert]

#77 White wire mystery solved!

I keep reading all I can to familiarize myself w/ this machine, since time and circumstance haven't allowed me to get out to use it. By accident, I just stumbled on the answer as to what effect the #77 wire has on these Sync 250's.

[I apologize for mentioning a different board, I hope it is allowed - but I wanted to give the members here the benefit of someone else's personal experience with their own Sync 250 even tho this person may not be a member here. Included below is the first and last posts from his thread.]

http://www.practicalmachinist.com/vb/fabrication-cnc-laser-waterjet-plasma-welding-fab/syncrowave-250-problems-132108/

Here is the problem described...

"I fired up my Miller syncrowave 250 for the first time in a few months the other day. I tried to weld some 1/8 inch test samples and could not get the aluminum to melt(not enough power). Even with the Amperage knob on 320 and the pedal completely depressed it would barely melt the edges. Hopefully someone on here can shed some light on this problem. Also when welding stainless (machine set to [electrode negative], high frequency [start] I could not get the weld arc started at a low current setting. I would get the high frequency spark and give it more and more pedal until all at once a powerful weld arc would melt the $h** out of my piece. Thanks."

- and the next paragraph is the OP solving his own problem by finding the same, hanging #77 wire [altho he didn't mention "#77", he does describe my EXACT discovery in my machine]

"Got er fixed. Put the board back in and planned to butten everything up to send it out for repair when I discovered a wire hanging. Attached to the lug at the end of the wire was a brass screw and nut that appeared to be spot welded or brazed to something. After a half hour of searching I found where the wire was previously connected. This wire comes from the small silver box under the control board and goes to a bar under the fan. Anyway, cleaned up the area, screwed the wire back in place and the welder is working fine. Thanks for your help."

[wb4rt]

Have you guys had any problems or issues with your older Sync 250's? Do you use them constantly?

I'm just a hobbiest, but had mine for over 18 months, and used it quite a bit. I have never had a single problem with it. I just wish I was good enough to use it to it's capability.

[USMCPOP]

Mine is rarely used, by my son.

[tbert]

Have you guys had any problems or issues with your older Sync 250's? Do you use them constantly?

[USMCPOP]

Hope it works out for you. I have a 1992 model.

[tbert]

Thanks Burt,

I hope it doesn't come to that. No offense. I am hoping that these machines tho old are tough, and that there is nothing really wrong with it. The little capacitor came in today, so I first need to replace that over the weekend. The wire number 77 problem I fixed initially, so the only thing left to do is replace this little capacitor.

I picked up some general supplies for the 9 inch air cooled tig torch, in case I get to the point this long weekend where I can do some test welds. Thanks for all the help. I welcome any suggestions.

[wb4rt]

Hey, tbert.

I've got that welder's younger brother (KF859913) sitting at my shop. The face and everything look exactly the same. I doubt the innards changed much from yours to mine.

Mine welds great (me not so much).

If you want to pick one question or area at a time, I will try to look at mine and send pictures of what is connected where. Don't ask 5-10 at a time or we will not make much progress. One step, resolve, next step, resolve. And since I work a full time job and weld as a hobby, it might take a few days to work through it, but I'm willing to try.

Lots of guys here have helped me for the past several years. Pay it back and pay it forward!

[tbert]

Wow how cool is that!… I wake up this morning to a call from my LW S asking for my email information, and they forwarded me the service manuals for all four of my Miller machines for free! Awesome, no excuses now for being clueless ha ha Ha

(yeah right… Just like having a welding machine doesn't make me a welder, having the welding machine info doesn't make me a welding machine mechanic! LOL)

But, thank you Miller!!

[H80N]

Machine- front syncro wave 250 - circa 1990 [ATTACH]34597[/ATTACH]

Lower half of same [ATTACH]34598[/ATTACH]

That is a great old machine...

[tbert]

Machine- front syncro wave 250 - circa 1990

Lower half of same

[tbert]

OK, so - the LWS says that Miller is emailing the Service Manuals I requested for my machines to their LWS office and should be available for me to pick up mid-morning tomorrow,...saga continues there.

Yes, you're right - those schematics are tough to follow in the Owner's Manual...especially when I'm not familiar with the lingo found there. I must say tho - the schematics tend to make more sense the longer you stare at them.

No, I haven't TIG welded w/ it yet. I was nervous to try it due to these things I am discussing here. I didn't know what or why or how detrimental to the longevity of the machine it was = so I've been trying get feedback before I start down that road.

If I understand correctly, which is a 50/50 chance w/ me - You're wondering about an 'amp readout' on this Sync 250, as in an actual gauge or meter? It doesn't have any - just the basic knobs and switches

[H80N]

mountains out of molehills...

did you ever try to TIG weld with this machine..??

you said it functioned fine in stick mode...

a blown RFI suppression cap and loose current sense wire from the shunt

will probably not stop it from functioning..

the reading on amp display will likely be missing or wrong...(until you reconnected it)

just wondering..??

[Bodybagger]

That screenshot was from the owner's manual available for download by inserting your serial number. Just have to know what to look for in the schematics.

I think that wire simply carries harmonics to the filter network FL1 to be drowned out, stabilizing the idle current that goes through the transformer while you're not welding and reducing "chugging" while you are welding (where the circuit lags in adjusting the output current because of voltage transients present).

In other words, you probably won't notice any difference at all, unless the filter network is shorted and was intentionally disconnected, but that would most likely have been done by unplugging the other end from the filter in its easily accessible location rather than the nut under the fan where you need three hands and an extra wrist to reach it.

[tbert]

ok, got denied at the 866-931-9732 Miller number. They state they can only send Service Manuals to LWS, and that I need to contact one of those...sigh, ok - my next mission...

[tbert]

Thanks!!

See?!… That's what I'm talking about!

Those are the type of descriptive pictures that I wish I was privy to all along! Even if they were a pay-per-view type of arrangement it would still be so worth it.

Bodybagger, do you have any thoughts as to what the effects on the welder may be if it was operated with the #77 wire off?