Miller syncrowave 180 sd output problem - please help!

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I have had my 180 sd for around a year or so. everything worked great until the other day. now when i strike an arc using my foot control in DC it puts out the maximum amperage that the amperage knob is set to. no matter how far or how little i push the pedal it maxes out. so if i set the amps on the welder to 180 it will put out 180 or if i set it to 60 amps it will put out 60-65 amps no matter what. i have checked the potentiometer in the pedal and traced it all the way into the welder to the circuit board. the ohms change with the movement of the pedal properly all the way to the circuit board. now, my question is, what is causing this? is it a bad part on the circuit board or could it be something else? i have already tried two different torches and i got the same result. i only have one foot pedal but i know the potentiometer is working properly. so i am at a loss. i depend on my welder for income so if i dont get this thing up and running in the next day or two i am royally screwed. please help as much as you can, i appreciate any advice you have to offer. if you need more information before taking a stab at it let me know, ill be happy to answer any questons or even take pictures. thanks in advance.
Reply:the welder was manufactured on 5/13/2003 if that is any help. also, when this problem occured a couple days ago i tried it a few times and it went away. so it seems like it gradually got worse to where the problem is now consistant.
Reply:does anyone have a repair manual for this thing?
Reply:Miller tech service, 1-800-4-A-Miller, during business hours.or http://www.millerwelds.com/communities/Click on 'Resources' at the top, to get your owners manual.9-11-2001......We Will Never ForgetRetired desk jockey. Hobby weldor with a little training. Craftsman O/A---Flat, Vert, Ovhd, Horz. Miller Syncrowave 250
Reply:i have the same post on the miller welding discussion forums and ive gotten some help but the problem is not fixed. i think im going to call miller tomorrow and then ill most likely be having a miller certified repair company take a look at it. there goes my bank account.Miller Syncrowave 180 sdMillermatic 180Lincoln Pro-Cut 55Bridgeport vertical mill
Reply:Originally Posted by LittleHad one do that. It turned out to be a Halls device on the input ? side. $60 for the parts, $80 for the diagnostics and labor. Little
Reply:If it welds OK on local then it will not be the hall.Does it have a local / remote switch, current control?  Check it.
Reply:the only remote i have is my foot pedal. there is no current control. basically my foot pedal acts as an on/off switch now but that wont work for me. im welding 16 and 18 gauge stainless and i need it to be aesthetically pleasing. so i definitely need the variable control.Miller Syncrowave 180 sdMillermatic 180Lincoln Pro-Cut 55Bridgeport vertical mill
Reply:i talked to a guy from miller and then i checked the wiring in the foot control for shorts. the foot control is fine, no shorts. the guy from miller said that it is something in my pc1 board. so i need to find a place locally to fix it in a timely fashion or i have to send it out to louisville and wait for my customers to knock down my door because im taking too long to finish the work.anyway, thanks for the help guys. i guess there isnt anything else i can do other than take the board in.Miller Syncrowave 180 sdMillermatic 180Lincoln Pro-Cut 55Bridgeport vertical mill
Reply:just in case anyone has the same problem as me i will let you guys know, for future reference, that the problem with my welder ended up being in the PC1 control board. so a local technician is repairing the board (for alot cheaper than a new board) and i will be going to pick up the welder in about 3 hours. Airgas in Detroit diagnosed the welder and then referred me to a local independent guy for the board repair. it took less than a day to get it done. i am very happy.Miller Syncrowave 180 sdMillermatic 180Lincoln Pro-Cut 55Bridgeport vertical mill
Reply:I also have a Miller 180. It has been going through gas solenoids and runs very hot. I weld on many Miller machines and if I put a root in at 70 amps at work, I have to bust my welder down to about 50. I took it back for warranty work today. I recently did some stainless square frames and had to turn it all the way down to 10 amps and still it tried to burn it up.
Reply:Originally Posted by 7A749Yup. Like Cruzier told you on Miller, if the remote checked out, most likely the board. Technical manual usually points to it as a "blanket" cause after all the other stuff is no longer suspect.Where did you get the board repaired? I'm in Lansing. Handy to know. I send all mine to Gastonia, NC.
Reply:and i am very grateful to cruizer, if it wasnt for his help i would probably still be standing around scratching my head. he pointed me in the right direction and i was able to get it taken care of in good time.Miller Syncrowave 180 sdMillermatic 180Lincoln Pro-Cut 55Bridgeport vertical mill
Reply:Originally Posted by 7A749PM me their number if you have it, or at least what store they are. I don't deal with AirgASS here. They are extremely overpriced & cocky.PM me with a number if you got it. Thanks.
Reply:Hi turboitall,I realize this is from an old post but would you have the number for the guy who fixed your 180 SD pc board? I have a bad board and need it fixed.Thanks in advance, Joe
Reply:guy hasn't been on here since October of last year, might get lucky if you send him a pm, he might get an email notification & then see what you are asking miller 330a bp TIGmiller dynasty 200DX TIGmillermatic 185 MIGthermal dynamics cutmaster 101 plasma cuttersnap-on YA5550 plasma cutterhypertherm powermax 30 plasma cutterbaileigh CS225 cold sawetc....
Reply:Hello,I have been having a slightly different but related problem with my Miller Synchrowave 180 SD. I realize this thread is older, but I am looking for someone to point me in the right direction. Thank you in advance for your time reading this...I will reply below with the serial number, as I'm away from the shop. I know it begins with the digits "LC". I bought the machine new in 2001, and it has the digital display for V and A, has adjustable post flow, fan-on-demand, and balance control.I just moved to a new shop location (the 180 SD took a moderately bouncy ride on a trailer). I strung a shiny new branch circuit to the welder on a 50A breaker. I discovered the following problem: When in DCEN or AC, the welder will only output 35-40 Amps, as indicated on the display, and the heat is correspondingly low. HF is working for DCEN start, and continuous with AC. If I put the machine in stick mode, it blazes away with 120-130 Amps no problem. There are no HLP codes showing, and the machine is in the default medium start power mode. The machine has fewer than 57 hour, and ~10K cycles. All visible connections inside the machine appear clean and tight. I cleaned and confirmed 0.012" spark gaps. With no load on the supply wiring I see 248 VAC on my DMM.Here are the conditions: (A) I have the knob on the front panel pegged all the way to 180 Amps, foot control connected. 3/32" 2% thoria, mild steel. All connections from machine to torch, collet, tungsten, ground clamp are clean. Argon is the gas.(B) Front panel knob at 180 Amps, foot control disconnected, jumper between pins A and B on circular connector. Same result, 35-40 Amps on the meter.I spoke with Miller. The tech said that the main board (of course) is the "problem". He said that since I have good output in stick mode that the SCR's are probably ok, and that I have plenty of input power (I was briefly worried that I under-engineered my supply wiring but satisfied after seeing good output in stick mode). He suggested I check the reference voltage across pins C and D on the front panel connector, and that if I have something other than 10 V, then a main board problem is confirmed. I am hoping to get to an answer more specific than "replace the main board". I am silly enough to pull the conformal coating off and remove and replace an offending component, if I can get advice supporting that. I have the skills to do so, but I'm also more adventuresome than is sometimes good for me. If it's just a voltage regulator or a Hall sensor, I would gladly get in there and attempt the repair. If the majority opinion here is that I should cough up the $ for a new main board, then so be it.I will post later today with the serial number and the results of the pin C to D voltage check.Thanks again.rS
Reply:Here's the MILLER site with 180 issues. http://www.millerwelds.com/resources...archid=1054683
Reply:Thanks BD1. That link doesn't seem to work. It gets me to the Millerwelds site, but says, "Sorry no matches, try different terms"Just in case it matters, my serial number is:LC578879I did the C to D test per the tech's instructions and got 2.2 VDC, instead of 10 V. So there's a ~1:5 ratio of actual vs. expected on the Vref and on the output amperage.I'll put all this over on Millerwelds too.Thanks again.
Reply:Make sure the panel current control is turned all the way up or you won't get 10vdc.C to D varies 0 to 10 with panel control setting. Remember the remote control only goes from 0 to panel setting. Might be better to think of it as 0 to 100% (0 to 10)
Reply:check the potentiometer in the foot pedal. I just repaired one at our shop doing the same thing. do these use the 14hd foot pedal? if so its the belt driven device in the pedal, should get 10 ohms either way of resistance if I recall correctlyLast edited by sausage450r; 10-27-2014 at 02:07 AM.'14 HTP invertig 221Thermal Arc 201ts'15 HTP 2400'13 Hypertherm Powermax 30Esab 875Esab 251Clark Metal Servicespecializing in stainless steel exhaust systems
Reply:Thanks for the replies! The 2.2 V is with the knob set to 180. I will look at the pedal again.
Reply:If you have only 2.2vdc C to D  we have a problem. Just looked into the tech manual and found this works a little different than the older syncrowaves. Pin C should have 10vdc on it and current control setting will make no difference. There is a micro controller on the pcb that takes the signal from the panel current control and the remote control and then it sets the signal to drive the welder output.If panel control is good and only the remote is low. You have a problem on the pcb. either the 10vdc power supply has failed or the remote control driver has failed.VR4 is the 10vdc regulator. A1, R14, D1 is the driver.(rc6 pin3) Make sure pin 3 is not shorted to ground or have low resistance.D1 is a zener diode and could get damage by a problem in the remote. Or strong HF in the remote control cord.
Reply:Wow. Thanks! I took a look at VR4 and was drawing out the A1, A3, and A4 connections and resistor networks trying to backward engineer the control circuit. I measured +15 VDC input to VR4 and +10 VDC output from VR4. So I think the voltage reference is good.I followed things up through A1 and found +2.1 VDC on pins 6 and 7, and +2.45 VDC on pin 8.I hadn't yet wrapped my head around whether the problem was in the LF347N quad op amp or if there was a problem in the feedback between pins 8 and 9.I've been trying to get my hands on a tech manual, as I would really like to do a component replacement on the board. I'm sure it's not a surprise that I can't just buy the manual. Any chance you could point me to a drawing or tech data? I've already ordered a new board, but I would love to repair this one!Also, Cruizer has been really helpful over on the Miller forum. On his advice, I confirmed +24 VDC from front panel pin A to ground.  The pedal checks out fine.
Reply:check your private messagesOriginally Posted by rws08aI've been trying to get my hands on a tech manual, as I would really like to do a component replacement on the board. I'm sure it's not a surprise that I can't just buy the manual. Any chance you could point me to a drawing or tech data? I've already ordered a new board, but I would love to repair this one!Also, Cruizer has been really helpful over on the Miller forum. On his advice, I confirmed +24 VDC from front panel pin A to ground.  The pedal checks out fine.
Reply:Originally Posted by felixdkatI'm in the same boat.... wondering if you had any luck?I have done component level work for a few years now and have a few scopes as well... if that helps...cheers,fdk