330 a b/p HF Problem

[Jmcghee]

Welp, it looks like I’m up & running! I swapped the fuse out & spent the last couple hours putting it through its paces. Ran a bunch of beads on carbon steel with HF start, fussed around with the HF adjust & got it where I like it, and then ran a bunch of AC beads in continuous on aluminum,...

[Jmcghee]

This one is a totally different style... it’s the sausage-shaped type that fits into copper “fingers” on either side. I grabbed two (an extra just in case today & will fuss with it tonight. I’ll keep you guys posted.

BTW- thanks for everything, this place is great

[Jmcghee]

Well after an unreasonable amount of searching, I finally found the fuse (more or less exactly opposite of the switches/HF in the back bottom of the machine) and sure enough, that one is blown. This was my first time taking that side panel off, and it’s waaay dirtier than the other side. There’s...

[Jmcghee]

Same idea but looks older to me. Also noticed the diagram for the first time when I grabbed that pic:...

[Jmcghee]

I’ve got a machine shop, but no oscilloscope unfortunately

I’m in central Illinois

[Jmcghee]

The meter reads the same (.5) just touching the leads together with nothing in between.

Ill call tomorrow and verify the serial/manual/year. The machine “feels” and looks old (similar to my other welder which miller verified as 1966) for whatever that’s worth. Not sure if this helps...

[Jmcghee]

It does yeah... I reset the gap to .009 at the get go

[Jmcghee]

Ohm’d the switch out, & it appears to me at least to be working correctly. .5 in both directions, and wiggling it around with the meter leads clipped didn’t create any sort of intermittent failure

[Jmcghee]

Serial is W527655 which I believe puts it at 1970. Aeronca41- you actually walked me through a problem with my other welder (wound up being a diode) about a year ago... not sure if you recall.

I hadn't really considered that the switch could be fried, seems like a pretty simple contraption...

[Jmcghee]

Hey guys-

I just picked up a 330 a b/p to replace my old(er) Dialarc and am working on getting it all set up. I wired everything in, set up the torch, ground, etc & fired it up. HF was in the “start” position and it fired up as it should, & quit when I struck an arc. After working...

[Jmcghee]

The diode came in yesterday. I swapped it out, fired it up, and I'm back up & running! Thanks again everyone for walking me through it

[Jmcghee]

You guys were right... the beeper selection has a ceiling below the resistance I was getting (300 I believe). I selected a higher range, and presto. 3 of them check out & one is trashed. Should I just replace the one, or all 4 & the resistors while I’m at it?

[Jmcghee]

I’m hopeful for the transformer as well. There was no smell, smoke, pop, etc.

Isn’t it extremely unlikely that all 4 diodes failed in a matter of hours without something else causing them to?

[Jmcghee]

I suppose I didn't explain it that clearly... the one I'm calling "shorted" had continuity (~.05 ohms, meter beeps) in both directions. The other 3 show absolutely nothing (no beep, no reading of any sort). Not even a little blip when I first touch the leads... the same result as if you touched...

[Jmcghee]

Well I followed the above test, and it looks like all 4 of the diodes are bad. 3 of the 4 had no continuity at all (0 reading on the meter) in both directions, and one of them was shorted in both directions. I have to imagine something else in that circuit cased them all to blow?