Millermatic 175 Welder Repair

A coworker asks Iain to look at his dead mig welder. After looking inside Iain finds that the circuit board is burnt. What could have caused it? Can he fix it? Watch the video to find out.

[@troy3052]

Great video I can understand!!! I love it no annoying music, yelling, playing up to the camera!!! Thank you I wish I found your video sooner, I would have saved $400

[@gregphillips6699]

Excellent video. I learned how to troubleshoot electrical problem better and never even tried to fool with a circuit board on anything do to lack of understanding but now I see. Thank you.

[@highman9836]

Very impressive troubleshooting and repair!

[@mikeziviello8789]

well done, a great share, good explanation, good camera work, I actually watched the entire vid. great, "bad solenoid, bad solenoid"

[@iainportalupi]

Mike Ziviello thanks!

[@stefanczechorskidds5536]

Iain, you really provided a excellent "how to" video here: your method is not limited to just welders, but many electrical devices! Your logic and manually tracing the path of each wire are also universal and thus many, many DIY'ers can apply (not just electrical nerds) ! Circuit boards, schematics and electrical components can be very intimidating (to the lay person) as there usually isn't anything to "see". Sure, sometimes a DIY'er may strike out; but here you show a method that demonstrates it is worth a TRY! Thank you!

[@iainportalupi]

Thanks for watching! Sometimes even electrical nerds such as myself come across schematics or circuit boards that can be intimidating. The best thing to do is just approach it logically and systematically and it usually sorts itself out.

[@xyloeye]

I had this same issue with my MIG 180. The control board was fried due, I think, to the slow death of the gas valve. The valve coil is 240 volts, so when it shorts, it's apparently disastrous to the board. I love my old transformer welder but the parts are stupid expensive - $450 for the board and $110 for the valve. Still, my welder is back in business. The new inverter equivalent is $2100! Thanks so much for the tip on checking the valve coil. I probably would have plugged the new board in and wondered why it wasn't working.

[@MysticMetals92]

Very knowledgeable young man.

[@iainportalupi]

Thanks!

[@chrisshorman522]

Thanks for the video Iain. It was quite helpful along with the Everlast repair video. I just finished fixing my friends Miller Diversion 165 with a burnt trace and nuked hardware. Good luck finding a Miller schematic on their boards. They wanted $1,700 for this board and I fixed it for less than $50. Just wanted you to know the work you put in was very helpful.

[@iainportalupi]

chris shorman I’m glad it was helpful and thanks for watching!

[@aguilargutierrez4]

Great video I learn a lot and hope you get more welder, plasma cutter etc, to fix and share the videos 👍🏻

[@iainportalupi]

agguilar oh yes, there will be more welder repair videos in the future.

[@ismaelrivas318]

couldn't of done it better. you are the man.

[@FlyGuy2000]

Awesome work! I just bought a used (working) MM175 and you saved me the trouble of cracking it open to look around. :)

[@carloscastaneda8302]

Lain, I have a miller 211 with a buzzing relay, fan not kicking on,tested and no current going to fan motor and if I disconnect the plug it has 120 volts coming from rc1 3 from the board and relay quiets, I also connect the fan with 120 volts and it is working outside of the welder, the only thing I didn't know if with 240 is working since I remember when I plugged to 240 it smell like burning Thanks in advance! This video helped me a lot on fixing my miller 135 by changing the ptc1 The way you explain is very easy to follow and understand!

[@stephanlemaire]

Thanks for your video. It will help me to found where is the issue in my welder.

[@mtrltoolman]

Good job man, thanks for sharing.

[@iainportalupi]

Thanks for watching!

[@timothybruce1242]

Watched this video and turns out to be exactly the same problem with mine, exactly, this video is a great help, wonderful. Thanks.

[@captainchippy8559]

Bravo! Very nice job

[@samk1201]

How about going into more detail on testing the capacitor? You started the video suspecting the capacitor because of the sides that pulled in and the residue at the vent. Thanks. Great information.

[@gregmiller9676]

Great trouble shooting. Can you show the capacitor being discharged?

[@mechman4]

thanks for doing a repair video in this welder, I dont yet have a problem with my millermatic 175, but its good to know how to diagnose and repair my unit should it fail. Thanks ! :-)

[@LextechLighting]

Sorry to tell you, nothing wrong with that capacitor. ALL the 211 and 175 miller capacitors look like that, it’s how that company designs them. I’ve been in 30+ 211’s and ordered many new caps - all of which come like that. Phillips caps have long running vertical sections all around them, these are oval in the millers.

[@gtstangman96]

I'm about to replace a trace on my 140 Millermatic. It blew the trace for the fan connection. Checked the fan and it was a dead short. Now everything is ordered(via Amazon for the fan, electronic store for the wire, flux, and solder) to do the repair and I hope to have this thing going soon. Thanks for the tips. Will report back.

[@MrCharlesCurrent]

Nicely done, as always. 👍

[@iainportalupi]

Charles Builds Crap thanks!

[@arlenpinell6490]

Very well explained sir, you should be a teacher. If I can follow you anybody can!

[@Rhine_Labs]

I would have removed the terminals from the housing on the harness and made the jumper at the terminals. But good repair.

[@MegaNarcotics]

Awesome work

[@jimdunkle4823]

great video! my board was bad and it cost me $300 next time I'll check it out myself!!!! thanks

[@iainportalupi]

Jim Dunkle thanks for watching! The welder manufacturers are famous for just selling whole boards.

[@johnwalton2603]

Thanks, very informative

[@johnj2496]

thanks hopefully this will help me with similar problems with my millermatic 211

[@dementedbowine8681]

those explosion marks kinda make things easy you know what took a shit oh yeah im subscribing

[@rsanchez9192]

Why was I expecting him to have a power driver after listening to his electronic prowess

[@richarda7704]

Nice troubleshooting, I love your sarcasm. What was your experience like when you ordered the solenoid? were you able to go directly to miller for the part?

[@iainportalupi]

I got it through my local Airgas.

[@mooseymoo1328]

Not just repairing trace and do "fire in the hole" was nice to point out! What was ohm reading on new coil/solenoid?

[@rotax1224]

Thank you so much.You are great

[@iainportalupi]

Rotax 122 thanks for watching!

[@legalsolutions07]

Good video. I'm having an issue with my Lincoln 140c mig and I'm hoping u can help. It no longer arcs but it powers up, the fan works & it feeds wire fine. I checked 4 voltage at the neg & pos where the leads hookup but no voltage. My questions are; 1) Should the transformer b tested 4 voltage 1st? 2) Should the rectifier be checked next and can it b tested while installed or should it b removed? Should the potted board necessarily show some signs of burning on the underside if I have a band transformer or rectifier?

[@djisydneyaustralia]

That's possibly weld voltage introduced to trigger circuit?

[@iainportalupi]

No, that was the 240v coil in the gas solenoid shorting out.

[@morganescamilla163]

Thanks bro you help me a lot with this video

[@luisgodinezperformance]

Hello, I have similar problems with my Miller 175 machine, can I contact you?

[@drewberrynews3875]

great vid on how to diagnose problem. Just a question: How come you didn't just repair the trace rather than leave the jumper wire? Just curious.

[@muhammadayaz6536]

Very good sir

[@iainportalupi]

Thanks for watching!

[@djisydneyaustralia]

8:24 please don't do that, when you can see visible scorching do unpowered static tests first , I repaired welders for my dad's business initially and was time and time again bewildered when he'd forcefully make me do a power test when I'm " wasting time doing a static test and fortunately just deserts were served on two occasions that went bang causing significant damage, I continued doing it my way, the right way.

[@markplease]

You aren’t by chance near Fontana CA, my Miller blew a mosfet and I could use some help repairing it.

[@iainportalupi]

I’m on the east coast.

[@aguilargutierrez4]

Thanks great video, great explanation easy to follow, I have a plasma cutter that blew up and I will test the part to see if it fix it, if I can't find the problem can you help ? I can send a email of the burn parts

[@mohamadaldarwish6678]

Perfect 👌

[@windscribe1223]

thank you for this nice video, please i want to ask you, in miller spectrum 2255 plasma cutter, in electric diagram there is something ( circuit card assy) .... input filter. .. whats mean? .. is means electromagnetic noise filer. .. or its a protection for a three-phase power .. thank you

[@gerrycoffey1]

you should open your own welder repair company. Thank you

[@drewberrynews3875]

I have a burned spot where the solder joint is. The copper is still in tact but the pcb is burned where I need to put the thermistor. Anyone have a solution?

[@isalchimodz6114]

Mig miller140 felts abs doesn’t weld helpppp

[@morganescamilla163]

HOW I KNOW IF THE CAPACITOR DOES WORK I CHANGE THOSE PARTS BUT MACHINE NO TURN ON

[@johnnyinostroza5807]

I got a problem with mine but I do all test for continuity and it checks out. The feeder wont move ,but i jumped it with 6v and it works. Its a Lincoln weld pak HD. Any opinion? Need help

[@capitanvonchickenpants8492]

Us with cheap welders are led to believe miller welders are indestructible, I feel much better now

[@iainportalupi]

Lets just say after repairing MANY Miller welders over the years from little 120v mig welders up to diesel powered trailblazers I would never buy a Miller welder.

[@LincolnRig]

@@iainportalupi Somehow I am not surprised to find a comment like this, I have a diesel powered trailblazer.... and it's the reason I am here

[@elliottdiedrich3068]

I'm here to see if I can't fix the control board on a Lincoln Ranger 250 with less than 300 hours on it, rather than pay the $1,450.00 for a replacement PCB.

[@easytopleez33]

Do you do PC Board repair on plasma cutters??

[@franciscouriostegui2024]

Nice .. I think that happen to mine

[@lonniehall9006]

Where are you located?? Ky

[@matthewanderson3631]

Did you just unplug the gas solenoid, to test… I’m not getting continuity at the solenoid and I don’t want to fry my circuit board 😮😂

[@jamessaniano8684]

where u located my freind

[@pl747]

put a small fuse in that wire jumper wire on the board for the next time.

[@themechanicman3865]

Why doesn't anybody give a fool and depth tutorial on how to test diodes transistors while they're in the board so that way you can read your values of the transistor or diode or heat sink whatever it may be and then also post links to where to get that information so anything that has circuit boards you can troubleshoot yourself with a common ohms meter some people say you need an oscilloscope to put it underneath power but if something I feel fails on the board whether the board is powered on are powered off it's going to be bad and usually 9 out of 10 when things f a i l in a circuit board you can sometimes see discoloration around or sometimes not but I am wanting to find out how to test a board and find out exactly while the machine is off what diode transistor Exedra is bad on that board while it's in the board even while connected to other circuits there has to be a way to isolate so it doesn't interfere with any other circuits it's intertwined in or connect to you should be able to test that diode transistor exedra

[@Rhine_Labs]

You can also call miller if the machine board is a old non production Rev you can get the schematic form them. Will not let me message you.. See my blog steven rhine . com I have the schematics for the miller 375 plasma cutter.

[@franciscouriostegui2024]

I have. A miller 140 and don’t turn on

[@gtstangman96]

Same here, someone pulled the board out when I bought it, bought a board and it burned a trace on the fan circuit. So I think my fan shorted out, nothing else works on it.

[@aguilargutierrez4]

Why not use the schematic of the machine ???

[@iainportalupi]

agguilar I couldn’t get it. Miller was less than helpful.

[@aguilargutierrez4]

Iain Portalupi I have a miller plasma cutter and the schematic was on a sticker on the metal case

[@iainportalupi]

agguilar I thought they usually had them stuck in them but I couldn’t find one. I emailed Miller and they never responded.

[@aguilargutierrez4]

Iain Portalupi I found the manual here www.millerwelds.com/files/owners-manuals/o1324d_mil.pdf hope it helps

[@DickRichie510]

Thank you.. just in case mine breaks..