Used 280dx problems

[derrickd]

I'm looking at buying a used 280dx and tried it out tonight and had some trouble. I was welding 3/16 alum with 3/32 2% thoriated tungsten sharpened to a point, 100% argon set at 15cfm, 120a, 100hz, 80% balance. No pulse. Starting the weld, I would only get the high frequency sparks until I got over 50a on the peddle, and the arc was unstable unless I floored it and then backed off. Same story at the end of the weld. The arc would switch back to a bunch of sharp sparks below about 30a. We tried a Master re-set in the tech menu thinking it was machine settings, and it didn't change anything. We have the same machine at work, and it doesn't do this. Anybody have any idea what was going on?

[cruizer]

Unit is more than likely on a operator set program,( the reset may not erase those programs) as for the HF, since the unit is inverter based. HF is not needed for lower amperage. Still its likely running on a program. As the unit is very error sensitive and you didnt report any, that would be my thinking.

[derrickd]

You're right, it didn't set any codes or have any stored. How do you check for an operator program? I tried ours out again today, same conditions, and even after the arc lit and welding at 100a, the used one wasn't the same. It's a trade in at one of the LWS, we'll see if they can figure it out.

[piniongear]

I do not have a 280DX but it must be similar to my 200DX machine.
Get a hold of the manual for the 280 and look at where it lists the factory range of settings.
Then look at the 'advanced functions' in the manual. The manual will tell you which buttons to press and hold to get to the advanced functions (which are background menus)
Go through all the menus and you most likely will find a previous operator has set some settings that do not agree with your technique or the default settings.
pg

[derrickd]

Well, they called me up to come try it again. Said they did a program update, and reset all programs, and had another welder(a real one, you know, who does it for a living and all) try it who said it was OK. It's still doing the same thing for me, just high freq sparks if you roll on the peddle, when the arc finally lights, the amp display reads about 45a. They are blaming my technique, aka, operator error. Their solution was just blast the peddle, and then back off. I can't deny that it does work when you do that, but our identicle machine at work lights up as soon as the high freq starts. Doesn't matter if it's 10a or 110a. Does this probelm sound normal to you guys?
Edit to add that I had a 1/16 tungsten this time and was trying to hold a 1/16th gap while starting

[ccawgc]

Look up how to get into the user menus. You may have the wrong tungsten size set. You must set the right size here because this sets up the arc start
settings automatically. Make sure this matches what you are using. Also check your gas flow, if to high, to will see hard arc starting at low amps.
High gas flow cools the tungsten and the HF can't heat it up so the weld current can jump. with a 1/16 tungsten you should be able to hold an arc
down to the minimum setting. With out it blinking out.

[H80N]

Well, they called me up to come try it again. Said they did a program update, and reset all programs, and had another welder(a real one, you know, who does it for a living and all) try it who said it was OK. It's still doing the same thing for me, just high freq sparks if you roll on the peddle, when the arc finally lights, the amp display reads about 45a. They are blaming my technique, aka, operator error. Their solution was just blast the peddle, and then back off. I can't deny that it does work when you do that, but our identicle machine at work lights up as soon as the high freq starts. Doesn't matter if it's 10a or 110a. Does this probelm sound normal to you guys?
Edit to add that I had a 1/16 tungsten this time and was trying to hold a 1/16th gap while starting

Try Here

https://www.youtube.com/playlist?list=PL2xpKYa5d-68W9ql3jep0MOzcjw1CVgcM&nohtml5=False

[derrickd]

Thanks guys, as far as I can tell, every setting on the machine is correct, besides, they claim what I'm seeing is normal. All I can tell them for sure is that an identical machine doesn't do it. I'm not going to spend anymore time worried about it. I'm simply going to order a new 210dx.

[derrickd]

Hey guys, just an update. My 210dx arrived today, and I thoroughly read the manual. I'm %99 certain all the settings on the used 280 were correct. Bottom line, my new 210dx will also light a stable arc at around 11a with a 3/32 tungsten, and still go down from there. I still have no idea what was going on with the other one

[H80N]

Hey guys, just an update. My 210dx arrived today, and I thoroughly read the manual. I'm %99 certain all the settings on the used 280 were correct. Bottom line, my new 210dx will also light a stable arc at around 11a with a 3/32 tungsten, and still go down from there. I still have no idea what was going on with the other one

Glad you got good one........