Thanks for sharing the video. Mine has this problem. The wire feed speed is on “high” so it welds high and cold. I diagnosed my potentiometer to be still good. I’m hoping it’s that transistor. $9.95 shipped off of eBay.
You are welcome, a soldering iron and a screwdriver and hopefully you will be in business. Be careful when soldering the transistor and make sure it doesn’t get to hot when soldering the new one one! Hope it fixes your problem
This is one application where the old analog meter will show an erratic voltage change. As the voltage changes, a normal sweep of the meter needle will be smooth. A bad control will show an erratic needle sweep. I keep both on hand.
The part number is a TIP 142 transistor and just type that into Google or any other search engine and it will bring up several vendors that will have it. Not sure if the microchip shortage is having any issue on pricing but delivered it should cost you less than $10-$15
I wouldn't know where to begin to look for a transistor in my neck of the woods. I farm and used to be you went to dealership and told them what you needed. They went in the back and came back with the part. Now you hope they can figure out what part you need and wait for it to be ordered.
Now there’s Google and Ebay, Just type in TIP 142 Transistor and wait for it to be delivered. I used to work a parts counter years ago. I remember rummaging through a warehouse looking for what the other guy needed
@@lazyjmetalworks9626 I find myself ordering more of the stuff i need over the web these days. Have a new Hobart 140 that I've done some repairs and projects with. Nothing wrong with it. Just like to read up on what could go wrong. Stick welder since i was 15. Find myself reaching for the wire welder more these days. So convenient. I only use flux core. Most of my projects are outside. And as you know the wind likes to blow here in Texas. Slag doesn't bother me. Less of it with wire than stick. And i get better penetration than i would with solid wire.
Does anyone out there know the name of the part on the circuit board that reduces the line voltage (120V or 220V) to the lower voltage required for the wire feed motor?
Thanks for posting. I had issues with my 135 not welding. They have a component kit that I installed and now it welds, but cannot change speeds. Just full speed. Your video has helped and I ordered the transistor you mentioned.
Topper 2011 Thank You. I hope it fixes your problem. If it is only feeding at one speed, I would probably look at the potentiometer dial first but either way each component are less than $10-$20 combined so cheap enough to get each one.
@@lazyjmetalworks9626 Thanks Jeff, I will absolutely look at the Potentiometer. The transistor is cheap enough to order anyway just incase. About $1.80 shipped on Ebay.
@@lazyjmetalworks9626 Hi Jeff. You were correct. I checked the ohms on the potentiometer and it was flat out on full speed. It's a two wire with a some control board on it, so maybe a standard potentiometer may not work correctly. I've found a replacement online for $28, about half what Miller wants. Do you have a better source or part number I could go by? Thanks again.
Topper 2011 glad to know you found the issue. I don’t have a particular part number, I’m fortunate enough to have a very niche electronics store in my area and I was able to match up the Potentiometer with what they had on the shelf. $28 isn’t terrible considering the overall price of the welder, but try looking at some audio components sellers, that same potentiometer is often used on guitar amps, you can also try prying it open and cleaning the contacts. The part is jacked up as is so you got nothing to worry about taking a look inside of it.
Hi Jeff, just an update. I replaced the transistor and the speed still seems too fast for welding. Adjusting the power switch also seems to speed up the motor to an unweldable speed. I tried another potentiometer and that didn't work, so I tried installing a potentiometer in between the motor and power wires and I could then adjust the speed to a low enough weldable speed. It didn't last long and I was only able to make a few passes. Any suggestions?
Thanks for the video! That may be the problem with the machine I borrowed from a friend. The drive wheel doesn't turn at all. When turned on it all sounds like when it was working but drive wheel won't move at all. Will be checking it out this afternoon. Thanks! Additionally, isn't that an Aggie ring?
Yes indeed TAMU Class of ‘99. Gig em. Yeah check the board and if that transistor is fried it’ll probably be the issue. All of the components are simple and cheap. It’s a TIP 142 transistor off the top of my head.
@@lazyjmetalworks9626 Gig'em! Class of '75 myself...my eldest daughter is Class of '99 as well. Were you per chance in the Corps? I was & my son-in-law was Class of '98 & a BQ. Served in Iraq & now he's a police officer in Austin. As it turns out, the drive wheel just seemed to have jammed, but a little 'persuasion' helped it to perform as before! Glad to know where I can turn to for welding issues too...had a stick- welding class in middle school in South Texas but didn't do very much with it after that...now retired & getting back into it...seems simpler now than back then...still working on getting more 'professional' looking welds. Thanks for the videos, keep'em up!! ~Chris
I have a Hobart Handler 135 that will not feed wire ? I am not sure what is wrong I should check it for myself, the Miller dealer told me that it’s a common problem with the 135 and I need a new card that is obsolete. I think I will check out the voltages, I will have to order everything online because there is no one for miles
Thanks! Mine is doing the same thing. I almost need a 2nd person adjusting the feed dial as I weld. I can get it running well for a minute or two then feed dies down. Frustrating
Hi. I have a similar problem with my Hobart 140. Sometimes work really good but, some don't. The wheel feeder turns but, the wire wheel that feeds don't turn, like it where so heavy, you can see the little wheel turning but the wire doesn't move and I already put more pressure to the wire wheel but the wire doesn't move, did you think can be the same problem as yours? Thanks ahead for you help
I would bet that it is a similar speed control board but the transistor may be a little bit different. I wouldn’t hesitate tearing into it especially if it’s out of any “Warranty”
I know that my question will be so dumb, but the motor works without the clamp touching a metal? I mean, it have a secure system or something like that? And actually I changed this MOSFET with a new one, but the output doesn't give me more than 5mV ;/ Thanks for responding! Great video , is so helpful
When you say Clamp, I assume you are referring to the ground clamp? The motor will still work even though the clamp is not completing the circuit between the gun and the item you’re welding. If you have changed the mosfet, I would consider changing the potentiometer. I show how to test the potentiometer in the video and sometimes you can open the potentiometer and just clean it out. Thanks for the comment
You can check it with an Ohm Meter if you have one. On this particular one, I could look at it and tell because it had some minor cracking on the face of it. Search RU-vid on testing Transistors with a multimeter, there’s tons of good videos on how to do it
Seal Boss I’m in the Houston Texas area and I found a great little store called Electronic Parts Outlet(EPO) that has all the little electrical components you could need. You can also google TIP 142 transistor and order it online for $7-$10 bucks
I have a Lincoln 140 but lets say im welding something n while im welding wire speed slows down what can it be any advice that could help me out Thanks in advanced...
You need to disconnect the wires to the motor that dial you’re talking about is called a potentiometer but the only way to test that potentiometer is without having it hooked to your motor then you touch the wire leads
Vivian Randin I removed the entire speed control board, so the motor wires were not connected when I checked the potentiometer. I don’t remember if I filmed the multimeter while I had the potentiometer off of the board, but it would smoothly show increased and decreased resistance when I turned the dial
My Hobart Handler 140 MIG speed started sputtering but only when I get an arc.. it seems to feed ok when I pull the trigger not welding but as soon as I strike an arc it speeds up and slows down really bad... I wonder if this would fix mine?
For less than $10-$20 including shipping I wouldn’t hesitate to give it a shot. Its a TIP 142 transistor, and all you need is a soldering iron and the solder sucker/remover. That’s interesting that it seems to only happen when the welder “completes the circuit” Mine was erratic any time I pulled the trigger. After realizing that the potentiometer was not the problem and seeing the burned area on the transistor i was happy that it was cheap and simple to replace
I am almost certain, they little machines are pretty strong, especially the new ones (with 5 presets on the front instead of 4) I have a 135 for about 20 years, that was the only problem I had
You can try two things. #1 In front of the wire spool there's a spring, washer and nut. I have found if you do a count on the threads it likes between three or four threads in front of that nut front the right tension. #2 the roller tension is another big factor. There should be an adjustment on top of the two rollers. I generally keep mine a whisker past number three. My machine is a Hobart Handler 140. I know all machines are different but this might serve as a good baseline setting to help you get it tuned. A good fresh contact tip in the gun also helps quite a bit. I generally try to keep my welding gun lead as straight as possible.
Hi John, I’m not sure I understand the question. The motor itself is called the gear motor or drive motor. If you are asking about the part number for the actual motor itself I will have to look again and see if I can find it. I bought a replacement motor for it but didn’t end up needing it, however I still have it in my parts bin just in case.
Blake Cartwright I’m not 100% certain but I believe it probably will, the only difference would be the amp rage of the machine, the drive Mechanism will probably be the same
Lazy J Metal Works thanks, mine is doing the same thing, you can unclamped the wire feed tensioner and it won’t even turn with no load. I wrote down the part numbers you gave out. I’ll tear into it tonight , thanks for your help👍
For those of you with experience with the Hobart 140 or similar. It seems that it's a good buy for light duty stuff @ 120v. I'm interested for something for light duty tasks/projects for square tube etc. I'm just curious, is this one that is still recommended to entry level/light duty? I'd use a tank for mig, but not much use for aluminum etc.
Tim S. I would definitely recommend this machine. The one in the video is close to 20 years old and that was the first and only issue I have ever had with it.
@@lazyjmetalworks9626 Thank you, much appreciated. I think that's what I'll get.. I'm use to buying once kind of thinking (240v) but much of what I'll do is light and I like the idea of being able to take it with me. Thank you again for the reply!
