Lincoln troubles

[czechsonofagun]

My little Lincoln MIG, I had it for years, developed a problem. Pulling the trigger, the wire moves out of the gun but the welder makes loud noise and eventually - in 3 or so seconds - it will pop the outlet breaker.

Not while welding, just to get the wire rolling. I took the wire handling apart and the transmission is operating smoothly, the motor spins easily with fingers but it still pops the breaker. I suspect the wire feed motor got a short???

Ideas, anybody?

 

[flyerdan]

I would suspect the contactor first, since the machine idles without tripping and it does feed wire.

 

[Industrial Toys]

Never seen a worn contactor (welder or otherwise) blow an overcurrent device.

Sounds like a short. Maybe even shorted transformer windings. Does it smell burned? Is the Transformer crispy? How old, how much use? Does it always do that or only sometimes?

 

[crazyal]

Do you own a multimeter? If so I would unplug the wires going to the motor and measure the resistance. Not knowing how it's wired there's several pieces involved in the wire feed. The first place I would expect failure would be with the wire for the trigger since it's always flexing and is subject to damage from something falling on the hose or gun.

 

[TractorGuy]

Unplug it, pull the cover, and clean all the dust and cobwebs out for starters. I've had to do that twice on my SP100 since I bought it in 93. It didn't start making a noise but it would overheat and stop welding.

 

[czechsonofagun]

With the gun off it is still doing it. The gun control plugs into two blade contacts, I use a U shaped wire to make the motor run and the result is the same.

 

[Industrial Toys]

Maybe a shorted rectifier. Probably more likely than the transformer.

 

[user.69169]

Disconnect capacitors & repeat gun off test.
USE appropriate safety measures disconnecting capacitors

Dat don't work post serial number & code number from machine.

 

[WranglerX]

I am having trouble with this statement --->"Not while welding, just to get the wire rolling.".... The description is no consisting with any operation or problem with unit....

Most MIG welders use a DC motor for wire feed and operate on around 12 -18 volts DC.... If you suspect motor, disconnect it from control board and try running it on battery power.... IF it runs for for more than "3 seconds" wire feed motor is not your problem...

Probable best bet it to take it to repair shop and get estimate of what problem may be and what costs are to fix it..... Many times problem may be control board related, but without proper diagnostic you are just guessing.... And replacing parts by guessing gets very expensive..... IT may be it will cost more to fix little welder than to replace it.... Professionals diagnostic is probable only way to know what's up with it....

Dale

 

[Industrial Toys]

I do repair welders for friends from time to time. Not an EXPERT by any stretch, but I probably know more than my Mom and Sister combined, on the subject.

Most times, it's something quite simple.

It's a stupid Industry. I have worked on a friends Hobart MIG, similar in size to these Lincolns, and will weld no different, but without a single circuit board or transistor. I would buy one of those in a hearbeat if I came across one.

 

[czechsonofagun]

DL Meisen:

Yes, that's my next step, I took the motor out yesterday, will try to run it with battery.

The motor resistance is 13 Ohms, seems to be high but I don't know what it should be.

Toys:

What welder would you recommend? I used this little WeldPak100 for over 20 years and never had the money or solid reason to use anything but flux core wire.

The motor - if it's the motor - from Lincoln is 9SL7801 (whole assembly), over $200 shipped. I think it's time to upgrade.

 

[deereman75]

Sadly I suspect it isn't worth fixing. You can probably get a brand new lincoln 140 or better yet 180 for not much more than the repair would cost.

 

[czechsonofagun]

Sadly I suspect it isn't worth fixing. You can probably get a brand new lincoln 140 or better yet 180 for not much more than the repair would cost.

Yeah, you are absolutely right.

 

[czechsonofagun]

The motor checks out, spins nicely. By the sound of the welder - without the motor and shorting the gun contacts - it sounds like a relay switching on and having too much resistance.

 

[deereman75]

I had a blade welder on a bandsaw that would blow breakers. It was a bad contactor, the ruined contacts causing high resistance. If you can make a cheap off the shelf contactor work it may be worth trying that for the $10-20 it would cost.

 

[czechsonofagun]

I had a blade welder on a bandsaw that would blow breakers. It was a bad contactor, the ruined contacts causing high resistance. If you can make a cheap off the shelf contactor work it may be worth trying that for the $10-20 it would cost.

Thank you.

 

[czechsonofagun]

Life got in the way, welder is still waiting to be taken apart, it must be a short by debris in some inconvenient place.

 

[grsthegreat]

i had a weird problem years ago with my small 120 wire feed unit. when i went to pull the trigger, the wire would spool out but would not be gripped tight enough with the spooler mechanism and wire would loosen up and ground out on case. i dont remember if the breaker would trip though. been years ago.

 

[Will S]

The problem is not the motor. If the unit is back together, plugged in and power on, but not wire feeding, does it still trip the breaker? Of can it set there running, until you activate the feed trigger?

Have you swapped out the breaker, just to make sure it is not a bad (weak) one? My friend just down the road, had this happen to him just a few weeks ago. Breaker looked good, it switched on and off as felt normal, but it was bad. Voltage coming out was very low. Have you measured the A/C voltage at the welding receptacle (or at the breaker) while the welder is plugged in and powered on in standby? Or are you reading a significantly low voltage?

If none of this helps, I would troubleshoot the high-current DC power supply in the machine. Most likely it is a shorted filter capacitor, or high-current diode. Those are both inexpensive to replace. If you do not have the skills to do that, do you know anyone in the electrical or electronics repair biz (TV repair tech), or a ham radio operator? They would likely be able to help.

Good luck. Post back your results?

 

[czechsonofagun]

I narrowed it down to diodes. Two out of four don't check out by the meter, so I need to find M9661 - 40RU and M9661 - 40U. Of course they are on the heat sink deep inside the welder, but it's good to make a progress.