dialarc hf has no dc output.

[Meltedmetal]

If you know how to do it safely you can trace it hot with a volt meter. The voltage will disappear right after the problem. Or you can measure across each component and there should not be significant voltage showing except connected in reverse across diodes. Volt meters measure "voltage drop" not really voltage so if you measure the input to the output of a switch for example it should not show voltage even though the switch and power are on. I am speaking about the same lead in and out not across 2 poles. If you use good clip on leads you can connect them with the power OFF briefly turn it on & take your reading and turn the power OFF again before you touch anything to move your test points. Remember you must respect polarity in DC circuits. Watch out for capacitors. You need to discharge them after each power on as they can stay charged and burn your meter out and/or give you a nasty shock which usually causes you to yank your hand or head back and smash it into something else ripping it open and breaking something. Be careful, be safe and good luck.---Meltedmetal

P.S. ONE LAST WARNING: THERE IS EASILY ENOUGH CURRENT THERE TO KILL YOU MANY TIMES OVER PROCEED WITH THE UTMOST CAUTION.

[H80N]

my old dialarc hf has no dc output in straight or reverse polarity. ac and hf works. any ideas on what to look for and how to fix and is it going to expensive?

Is it possible that you are actulaly getting voltage out but not getting DC TIG arc start..??

Have you tried Stick welding in DC mode..??

Or leaving the Contactor Control Switch in the STANDARD position instead of REMOTE and measure voltage out between the terminals with a meter (should see an open circuit voltage guessing around 60vdc)

[Meltedmetal]

If you attempt the test procedure I outlined above turn off the HF as in check in stick mode or you will likely toast your meter.---Meltedmetal

[H80N]

If you attempt the test procedure I outlined above turn off the HF as in check in stick mode or you will likely toast your meter.---Meltedmetal

Good point..

[Hoss]

The hf is not turned on. I tried stick in straight and reverse, nothing. Ac works in stick and tig with or without hf. I traced circuits as best I could with a continuity tester an could find nothing amiss.

[H80N]

The hf is not turned on. I tried stick in straight and reverse, nothing. Ac works in stick and tig with or without hf. I traced circuits as best I could with a continuity tester an could find nothing amiss.

To me... it sounds more and more like a selector switch problem.....

or a disconnect between the transformer+magamp and the rectifier assembly

Do you have AC going into the Diode bridge..??

or voltage coming out at point #24 or at point #29 on either side of inductor "Z" ?

See the schematic , Figure 7-1on page 12

https://www.millerwelds.com/files/ow...s/O315_MIL.pdf

(you may nead to blow it up to read it)

[cruizer]

9 times out of 10, it's a winding failure at the stabilizer

[H80N]

9 times out of 10, it's a winding failure at the stabilizer

That would make sense........... (stabilizer # 027 218) ??

you are talking about the Inductor "Z" ... Right..??

[Hoss]

I don't know for sure what I am looking at. I can see it on the diagram but not on the machine. Sorry. thanks anyway for all the help. The guy I got it from is out of town for a few days so I will talk to him about a refund when he returns.

[H80N]

I don't know for sure what I am looking at. I can see it on the diagram but not on the machine. Sorry. thanks anyway for all the help. The guy I got it from is out of town for a few days so I will talk to him about a refund when he returns.

If you are still game...

you could take some pics of the inside of the machine, post them and one of us could circle it...

[Hoss]

I'll see what I can do.

[H80N]

I'll see what I can do.

it will look a lot like this.. The top one "A" Inductor, iron core

There will be 3 similar items inside the box... the Transformer, Magnetic Amplifier, and the Stabilizer/Inductor
the Inductor is likely the smallest of the 3

[H80N]

See Item #19 on page 1 of the parts listing...Figure A MAIN ASSEMBLY

Page # 24 of the PDF

https://www.millerwelds.com/files/ow...s/O315_MIL.pdf

[Hoss]

I see it. it is difficult to get to. I guess that I am supposed to measure the voltage at each end,yes? Do I measure from each end to ground or somewhere else? I know that I should know this but I want to be sure to do it right. How many volts should I be seeing? will it be ac or dc? If the winding is shorted shouldn't it show with an ohm meter or does it have to be live to check? If I have voltage at each end then what should I check next? I know its alot of dumb questions but I have not done this kind of stuff in a lot of years

[Meltedmetal]

For continuity power off- I don't know what ohms it should be but it should not be open which looks like "open" would match your symptom. It should not be shorted to the frame which I doubt as I think you would have some fireworks.

Voltage test, power on, HF off, set on DC, : I would expect to see close to max. ocv that looks like 76vdc between stabilizer input & and the electrode lead. You should see the same at the stabilizer output but if you don't the circuit is open between the 2. If you do have voltage at the out put continue downstream until it disappears.