330 A/BP tig high frequency

[FNG]

Help, I picked up a Miller 330 A/BP ser#P349977 and after a month I have no high frequency start. Spark gaps light up with the remote. I cleaned and reset tha gaps to .008" I held the ground clamp close to the electrode terminal to eliminate the torch or cable, no HF. The last time the HF worked it was intermitent and I think the spark was reddish? Thanks for any help fixing this problem

[cruizer]

Help, I picked up a Miller 330 A/BP ser#P349977 and after a month I have no high frequency start. Spark gaps light up with the remote. I cleaned and reset tha gaps to .008" I held the ground clamp close to the electrode terminal to eliminate the torch or cable, no HF. The last time the HF worked it was intermitent and I think the spark was reddish? Thanks for any help fixing this problem

Open up the case, dim the room, hit the pedal and see if the spark is jumping to something inside

[FNG]

Thanks Cruizer, I took off the side panel and tried that and didn't see any arcing or signs of bridging. I will try again tonite.

[H80N]

Thanks Cruizer, I took off the side panel and tried that and didn't see any arcing or signs of bridging. I will try again tonite.

This is a pretty common problem on these old machines... they live for decades in a dirty environment with a lot of conductive metal dust to foul up the works...

here is an old thread on the same problem.. that you may find useful..

http://www.millerwelds.com/resources/communities/mboard/showthread.php?32519-Miller-330-A-BP-won-t-strike-arc-without-dragging-tungsten-on-work&highlight=corona

[FNG]

Thanks for the link. I have spark at the gaps, but tomorrow I will try to isolate one capacitor or the other to check for failure. I took off both side panels, blew out some crud. At night in the dark, didn't see any arcing except at the spark gaps. Should the arcing be obvious? Any ideas where to consentrate my search?

[H80N]

Thanks for the link. I have spark at the gaps, but tomorrow I will try to isolate one capacitor or the other to check for failure. I took off both side panels, blew out some crud. At night in the dark, didn't see any arcing except at the spark gaps. Should the arcing be obvious? Any ideas where to consentrate my search?

Have you tried turning up the high frequency intensity control??

you should hear the HF buzz get louder (and brighter between the gaps) as you turn it up..

[cruizer]

Does the torch scratch start, or do you depend on the hf for starts? Might just be that the conduit inside the torch is hooped, also .008 which is recommended by some to my point of view is kinda tight. I gap em to 012. Way better starts, least wise for the transformer machines.

[FNG]

Thanks Cruizer and H80N. I will try that. Earlier I checked the HF intensity with an ohms meter, it shows some wear but it increases and decreases when you go from high to low. I had a busy day today so maybe tomorrow.

[FNG]

Ok, I isolated each one of the "mica capacitors" and the HF works with one but not the other. So I'll replace both and let you know how it works. Yes I could always scratch it but I wanted the HF to work for aluminum. Thanks again for all the help. What a great source of information.

[H80N]

Ok, I isolated each one of the "mica capacitors" and the HF works with one but not the other. So I'll replace both and let you know how it works. Yes I could always scratch it but I wanted the HF to work for aluminum. Thanks again for all the help. What a great source of information.

COOL... !! .. PLS Keep us Posted....

[FNG]

Ok I got 2 new capacitors from miller4less, I called Miller tech to be sure new numbers would cross referance. I installed them and now HF works. It's still slow to start, lag time between pedal and torch, but it works. Thanks for all the help.

[H80N]

Ok I got 2 new capacitors from miller4less, I called Miller tech to be sure new numbers would cross referance. I installed them and now HF works. It's still slow to start, lag time between pedal and torch, but it works. Thanks for all the help.

Glad to hear that you are up and running again..

[Prof100]

Isolating capacitors to check for a bad one for HF problem

Ok, I isolated each one of the "mica capacitors" and the HF works with one but not the other. So I'll replace both and let you know how it works. Yes I could always scratch it but I wanted the HF to work for aluminum. Thanks again for all the help. What a great source of information.

I have the same machine and it requires striking an arc. I have the machine since 1992 and use it sporadically. How did isolate each one of mica capacitors to determine which one was bad?

Thanks.

Bill

[migweldermike]

where are the mica capacitors

[H80N]

You will need to plug in your serial number and download the manual....

here...

https://www.millerwelds.com/support/manuals-and-parts

.