Millermatic 172 Issues

[mcman56]

I have a Miller 172 Challenger MIG welder. It is 10+ years old and has seen very little use. After sitting for some time, I got it out and had some problems.
1. The arc looked like a match that would not quite start. I changed the tip and it seemed normal for a few seconds but then went back to the low power look. I even tried max power with a .03 steel wire on 1/8 steel. The ground cable looks OK. Do I need to look inside the box or??

2. Gas is not flowing or flowing very little. I can close the bottle valve, hold the trigger on (when powered) and the pressure drops very very slowly and somewhat uneven. The pressure type flow meter will also stick.

With valve off, opening the connection between regulator and tank brings pressure valve to zero. Opening the connection on the welder side of the flow meter brings the flow meter to zero. I think this means that the regulator and gages are OK.

If it makes a difference, I last used it for Aluminum welding and it has an argon bottle. The flow meter says CO2.

Does that suggest I have a plugged line or bad solenoid? What should I check? When pulling the trigger, the drive makes enough noise that I can not tell if the solenoid is opening?

Any other suggestions?

Thanks,

Dan

[davedarragh]

"Think Outside the Box"

I have a Miller 172 Challenger MIG welder. It is 10+ years old and has seen very little use. After sitting for some time, I got it out and had some problems.
1. The arc looked like a match that would not quite start. I changed the tip and it seemed normal for a few seconds but then went back to the low power look. I even tried max power with a .03 steel wire on 1/8 steel. The ground cable looks OK. Do I need to look inside the box or??

2. Gas is not flowing or flowing very little. I can close the bottle valve, hold the trigger on (when powered) and the pressure drops very very slowly and somewhat uneven. The pressure type flow meter will also stick.

With valve off, opening the connection between regulator and tank brings pressure valve to zero. Opening the connection on the welder side of the flow meter brings the flow meter to zero. I think this means that the regulator and gages are OK.

If it makes a difference, I last used it for Aluminum welding and it has an argon bottle. The flow meter says CO2.

Does that suggest I have a plugged line or bad solenoid? What should I check? When pulling the trigger, the drive makes enough noise that I can not tell if the solenoid is opening?

Any other suggestions?

Thanks,

Dan

So you just turned it on, and pulled the trigger, eh? If a machine has set for a while, it's always a good idea to LOOK things over, under the lid, and elsewhere.

You said you last used it for aluminum? Is that a 100% argon bottle you have it hooked to? Did you use a spool gun, or try and feed aluminum through the gun? When was the las time you uncoiled the gun and blew it out with compressed air? Most C-25/CO2 regulators are "dual" scaled, but 100% argon isn't going to provide effective short circuit transfer welds.

Is your machine plugged into to the correct voltage? Are all your connections secure? Low gas flow may mean the gun isn't seated properly in the machine, or your bottle is about empty.

You should hear a definite "woosh" or "puff" of gas when you pull the gun trigger. Check your conections. Make sure you're using the right gas. Make sure your wire isn't corroded, and feeds easily. Check your tension.

Start from the beginning of the owner's manual, like you've never used the machine before, and follow the steps in order.

Dave

[Desertrider33]

For starters, you have the wrong gas if you're trying to weld steel with pure argon. Get the right gas on it (argon/CO2 mix) and see how it works.

[Maineiac]

Millermatic 172 issues

You can also check your line. Yesterday my brother was welding for me. He was using my MM211 and all was going well. Then the gas was not coming through. Now heres what happened. He has a bad habit of pulling the welder towards him using the gas/wire line. He pulled in out just 1/4 inch and that was enough so the gas was not coming through. He taught it was a gas valve,but it wasn't. Thank God I found the problem. I am not saying that is your problem but check your line to make sure it is pushed in all the way.

[mcman56]

Tightening all connections fixed the power issue. The gas flow problem was simply a bad solenoid valve. Oddly it looked fine but simply did not work. The replacement works fine.