Airco TIG welder, will not strick arc

Hey there, I have an old Airco 300 amp AC/DC Heliwelder V square wave that has been sitting in the garage for years. My father got it from his brother years back and it has been sitting ever since, I had some down time and decided to play around with it.

The welder seems to power on just fine, cooling fan starts right up. When I try stick welding with it, it will not strick an arc, it acts like the amperage is set way to low, I get a few small blue sparks but thats it. The same applies when I tried changing the polarity and tig welding with it. Using the foot contorl does not make a difference either.

I have checked the fuses, the relays on the board and the potentiometer for the amperage dials, they all seem fine.

Before I try and get ride of this thing, has anyone had a similar problem? Anyone got any ideas?

Double check the jumper bars for the input power, that they are set to the right voltage. Also check all of the connections for the leads, including the ground. Do you have a volt meter to check the open circuit voltage (output voltage with no load)? Should be around 60-80 volts.

One other note, Check to see that the controls are set for stick, or that the output contactor and ampere controls are set for panel control, NOT remote, (in case this was last used as a tig machine).

Show us a photo of the front control panel
Not sure who made this machine , but it could be similar to a Miller or Lincoln that someone is more familiar with .
On my Miller Shopmaster you have to have the contactor switch to ON to do stick weld .
Also look at the selector switch inside the cabinet. When you rotate to different settings , you are engaging different knife blades . You are also engaging some micro switches inside , when you rotate the selector . I know that I once had an expensive service call that turned out to be a minor adjustment of a switch.
This may not apply , but my Shopmaster has MIG, TIG, Stick capacity , and 2 different sources of ground leads depending on type of weld .
FBBob

You are just getting the background current. It is supplied from a small bridge rectifier on this machine.

Good chance its the control board. That's the smaller one of the two. Innovat corp repairs them. The last one I worked on had a bad voltage regulator on that board.

But before you send it in to be repaired pull loose the relays on the relay board and reseat them, the cables too.

I ended up buying both a 12+ and a 12- voltage regulator and replaced both of them. It looked as if they had allready been replaced some time in the early 90's, someone got a little happy scrapping off the protective coating on the board

I also found a bad capacitor and replaced that too. I am happy to say the welder works!! I have only tried stick welding so far, but it seems to work fine.

thank you

matt