[68ragtop]

So I bought a New Miller Syncrowave 180SD back in the summer of 2002. Used it 100% for smaller carbon steel work & nothing else. Then had to repair some aluminum & having zero experience with it, I just kept trying things until I found it would weld in DC mode, setting the polarity to electrode (+) this worked pretty well for small stuff, but the aluminum had to be crazy stupid clean. So I continued on thinking nothing of it.

Then about a year ago, I was trying to weld up something a little thicker in aluminum. Just too much heat being passed into the tungsten & it would blow it apart after a short amount of work time. I had a friend stop over who has a lot of seat time welding aluminum. First thing he did was flip the switch over to A/C & guess what. Almost no output from the welder. I told him I was never able to weld anything in A/C & He quickly determined there was something wrong with the welder. What the heck? All these years I assumed A/C was just for stick welding, so I never tried it further.

It will freq start an arc in A/C mode, but its almost as if there is only 10% power, or a bad ground. I took the cover off & adjusted the gap on the points, but that didn't do anything. Good 220 connection with ground.

Any thoughts on trouble shooting further? I would assume this welder should be able to do Aluminum A/C?

What bugs me is this has likely been this way since the day I bought it.

[dataway]

The syncro-wave ( I have a sincro-wave 250 about the same age) was basically designed to do AC aluminum welding.

Sounds like you don't have amperage control in AC. The syncro-waves had a circuit board issue for a few years, including mine, which burned out two boards ($500 each). Have you been using a thumb control or the foot pedal for amperage control?

I tracked my problem down to ( I think ) having the thumb control cable taped to the torch cable while using AC ... back fed interference into the board and burned something out .... happened twice, stopped using the thumb control, hasn't happened in the last 15 years. Although .... I didn't have amperage control in ANY setting, DC, AC etc.

Have you been using the Hi-Freq start for your DC welding? Just wondering, that's the way it was designed to be used.

Sounds to me like an amperage control problem ... since you wouldn't have any power at all if the AC transformer was gone, since that provides the DC power too after being rectified.

First thing I would try to flipping the big lever back and forth a few times (while the welder is off), if it has almost never been used the contacts could be dirty.

If I remember right there are some fuses on the main circuit board ... but you are going to have to pull the welder apart to find those.

I'll be honest .... the synco-wave was the best aluminum welder on the market for many years, considered the defacto standard ... but, I have never been real impressed with their quality ... mine burned out the two boards just out of warranty, and the on/off switch crapped out after a year or so and has never worked since ... I have to turn it on and off at the breaker. My two Lincoln MIGs have never had a single problem and I've abused the heck out of them.

If you do determine that it is a problem with the main board I have an old (burned out one) and a complete factory schematic and parts list for them. My welding supply shop felt so bad after I paid for the second $500 board that he let me keep the old board and gave me the "secret" schematic and parts list ( a lot of pages).

Also .... when they replaced the first board and the factory sent a replacement ... before the guy put it in .... noticed the exact same component on the board was already burned out .... so the factory was sending returned boards back into the field.

Miller Welding has a good forum. I'm sure someone there can help, it's probably a known issue. But you'll probably have to take some heat from people ripping you for not being very familiar with your welding machine

[dmorg1]

Ya, a positive electrode can't take very much amperage.

I am not familiar with the 180 machines but the 250 and 350 machines use this for aluminum



AC
Process = TIG
Amperage = REMOTE
Output = REMOTE
Start Mode = HF CONTINUOUS

Move Amperage Adjust Dial to desired amperage

Use straight argon or helium mix.

Dave

http://www.stellarmachine.com/

[68ragtop]

Thanks Guys for getting me started with my research.

I do have a thumb wheel & used it a lot in the beginning. I found it to be a pain & switched back to the foot pedal. I just like the instant control with my foot & pulsing Amperage. Haven't used the thumb control now in over a decade? But yes, I did use it quite a bit at first & I suppose it could have damaged something when the welder was brand new & I didn't know it. It does freaq start normally in DC mode.

I'll do some testing to see If there is any change to pedal position & amperage on the dial. I can turn the dial all the way up & mash the pedal all the way down & all it will do is clean the aluminum. So it arcs /starts. But does not sound at all like it should. very benign. Not that typical loud crackle you hear from aluminum A/C welding.


The process switch looks great, a little lube grease on the contacts, but clean otherwise. I still have the cover off, so further trouble shooting & tearing in deeper is no problem.

[68ragtop]

Data, when you lost you control board, did the DC process still work? I can DC + or - with no issues at all. Only A/C that isn't working correctly.

I will test A/C mode when I get home to see if I can tell a change in the arc based on Amperage controls.

[Pearlbluebird]

Also check all the fuses going in. Maybe enough to power up but not weld

[dataway]

I can't give you a positive answer ... but I'm 90% sure I lost everything.

I can tell you how to test it though ..... switch the amperage control from "remote" to "Panel" .... the pedal should then work as a switch to turn power on and off. This "should" bypass the remote amperage control circuitry and let you know if the problem is there, or somewhere else.

Should be able to set the amperage knob to like 60 amps and the pedal should switch on the torch, but not control the amount of amperage ... it will just be full 60 amps on or off.

I'm no welder technician .... but the old syncro-waves use a circuit board the size of a computer motherboard, my guess is AC and DC amperage circuitry are completely different and one can burn out and the other still work.

The problem with my board was visible on inspection ... you could actually see a burned out resistor and capacitor.

[68ragtop]

I didn't think I could switch that. where is that control? The panel has always been my "limit" adjustment & the pedal went from 10A to what ever the panel dial was set at for max. 10A-180A I think?

Thinking maybe that's an added feature on the 250?

I will be home in about an hour & I will do some deeper testing & report back.

[dataway]

Here are some photos of the main board.

From the back side you can easily see the location of the burned out component. Normally I am the type of guy that would trace it on the schematic, find the value of the component and replace it, but it is next to a transistor which I figure is also probably damaged, and things would get more complicated. So I figured I would leave it be and save it for future use if I could find an electronics guy that was confident he could diagnose it.

Also is a picture of the LEM module ... no I don't know what that is, but it's some part of the amperage control circuitry.

If and when you find the problem, and you don't want to pay some welding shop $1000 to fix it, I do have the schematics somewhere that a tech could use to possibly fix the problem. I replaced the boards myself since I didn't want to cart the 400# welder an hour away and have to go pick it up again.

PS. My 250 has a toggle switch on the panel to go between panel control and remote control. When set to remote it operates just as yours does, max amps set on the panel. When in "panel mode" the pedal is just a switch and it goes from right to the max amps set on the knob. The switch also might be somewhere else, like close to where the pedal cable enters the cabinet .... I'll look up your welder and see if it has one.

[dataway]

Looking at the manual for your welder it looks like it auto senses a remote ... so IF a remote is plugged in, it uses the remote. However it CAN be panel controlled if stick welding and no remote plugged in.

My guess is they make an accessory pedal for your welder that allows for using panel amp control that just acts as a switch. It mentions in the manual that if a remote (pedal or thumb) is plugged it AND has the capacity to control amperage that the machine will automatically use it .... so I assume if you plug in a pedal that CANNOT control amperage it will just act as a switch. Although this is besides the point and doesn't address the problem you are having now.

[dataway]

Did a search on that welder .... it's kind of known for issues with the circuit board. Other things I'd check .... pull the torch apart and just check for another funny going on, no broken tungsten etc. Check power connections and wires ... evidently AC is more sensitive about that kind of thing.

Found a post or two that sounds like the exact same problem I had with mine, with the exception that at least one guy replaced the board components himself for just a few bucks instead of buying a new one like I did.

If you go to a welding forum ... brace yourself, lots of dicks that will bust your nads about pointless stuff.

[68ragtop]

Well, I got home and hot footed it out to the shop. What happens is I can set the panel dial on 10 amps or crank it up to 180. Barely touch the pedal or hold it all the way down. No change at all in the arc whatsoever. I Flip it to +DC & I have full power from 10A to 180A

So, it does act as if there is no power adjustment regardless where things are set when in A/C process. Acts like its stuck at 10A

I wouldn't think it's the pedal or dial seeing DC works normal.

[dataway]

Looks like it is repair shop time, or peruse the Miller forum (make sure you have your serial number handy) and check for fixes. You'll find it's a common problem.

There are people on that forum that actually repair Miller welders so that is the place to go. I'm guessing a Miller tech at a repair shop could probably tell you what the problem is without you bringing it in, and might be able to point you to a fix.

I would say probably 95% that it's the AC amperage control circuit.

I'm guessing a replacement board would be in the $800-1000 range, I see places that list repairs for the board around $400.

However ... it still could be a lose wire, a small component, or something cheap. If you have NEVER used it in AC before it could be something that was never hooked up, or a lose wire right from the get go. Also since yours probably has auto sensing supply voltage hookup you might want to make sure you are supplying it with enough power, AC usually requires considerably more than DC.

When my Syncro-Wave dies I'm going to haul it away and buy a $1500 super duper Chinese Inverter TIG, there are a few decent ones out there now and I'm just not going to pay the stupid prices that Miller and Lincoln charge anymore. Unless you are buying an industrial unit you are just getting foreign made stuff from Miller anyway, and the repair and replacement prices are just crazy, and the service is no better than you'd get from the MayTag repair man.

Heck, the broken on-off switch on mine is about $250 ... for a freakin switch, and it doesn't cross over to any other aftermarket product I can find. If Miller and Lincoln don't get their act together they will cease to exist before long. The days when they were the only game in town are long gone.

[68ragtop]

If it comes to a board, I'll just sell it as a steel welder. If it was working correctly I doubt its worth much more than $1000. I was reading were guys tested amp control by flipping it to stick mode, unplug the pedal & strike an arc with the tungsten. I'll try that before calling Miller. I did pull the board just to get a visual. Everything looked fine from a connection & component perspective, but of course than means nothing from whats going on. just nothing obvious.

I did find where people were having the same issue, but nothing that was just on A/C like mine, so maybe thats a good thing?

[dataway]

It's a pain, but before getting rid of it I'd try to go through all the connections and make sure everything is right. Welders have a ton of connectors, plugs, screw terminals ... just takes one to keep it from working right.

You have to look really close at the board to spot a burned out component, sometimes they are just discolored a bit ... can also be a failed IC in which case there would be no visual evidence at all.

It's a shame Miller put out these products ... they must have had tens of thousands of failed boards on the syncrowaves between 1995 and 2005. I'm not one to become loyal to any product, but my Lincolns have better build quality and have never failed in any way. Can't say the same for my Miller welder and plasma cutter.

If you find a solution let me know ... always interested in that kind of thing.

[68ragtop]

I called Miller. They gave me a quick run down of tests to try. The Board visually looked good. No hot spots, burned foil, blistered Caps, etc.

I am not very optimistic of it just being a wiring issue. The one thing I did find in all my searches however is most people that loose the board, seem to loose both DC & A/C So if there's any hope, its that I can't find any threads on this welder being problematic on A/C only.

I'll update what I find from here.

[68ragtop]

Well, that didn't go very well.

I was told to test the open circuit voltage, which is putting the welder in stick mode, DC +electrode setting & read the voltage between the electrode connector & the work connector. I was told it should be about 80vdc. The tech expected I would find a voltage drop in A/C mode. Actually I found I only had 31vdc on all three settings. So I called back & the second tech told me I should have 80vac, not dc. Well I tested that & I have 40vac in all modes. I asked what I could look for & he basically said the board is junk. Almost seemed like an easy way out of the phone call....

[dataway]

What sucks is there are probably only a couple of different small components that all these boards are burning out on the board that cause these symptoms that could be replaced for under $10 if people knew which ones they were.

Doesn't sound like the techs are that well versed on the testing.

[68ragtop]

Seems odd that the boards have no shielding whatsoever in the cabinet. Must not be required, but I gotta believe there is a lot of RF flying around in there!

I have been studying the schematic & the design seems simple enough from a component standpoint. Wish there was a schematic for the control board. Or should I say a public one This welder has likely had this AC issue for ever, but now that I know its there, I either want to repair it or replace it. Seems the market on this particular model is anywhere from $800 to $1200 & if the control board is over $700 I would say I am better off selling it as is & buying something more reliable. Not sure what its worth now. Does awesome on anything DC. $300, $500? Less? I think It was $2000+ new, but I am not positive on that. I guess what urks me the most is this issue was likely there when it was still under warranty. I only tried A/C aluminum once & it did nothing, so I made do with DC positive E. Miller tech didn't believe I could weld that way, but it actually works. But has to be new aluminum, stupid clean & not very thick. All the heat goes to the tungsten in that mode.

I'll keep researching, but my hopes have dwindled into a shoulder shrug.......

[dataway]

I found numerous businesses that seem to specialize in diagnosing/repairing welding machine circuit boards. Typically about half the price of a new one .... and my guess is more reliable than a new one from the factory.

The repair places are probably making a fortune, I bet there are only about three different ways these boards burn out and they probably have them all figured out by now.

Do a search on the part number you find on the board, not the part number in the book, but the one on the board.