250EX issue

Quote:

Originally Posted by Blaze

I decided to try lift start tig. Couldn't get it to work but after multiple tries it finally started working. Changed back to hf start and the machine started welding good again. The hf still stutters sometimes but is now changing over to a steady Arc. I don't know what makes the machine change from hf start to a welding Arc but it finally is switching. Anyone know how that works? Also what role does stick out length perform during ac welding or any welding. Really would like to know how the hf to welding Arc switching works. So happy but it still stutters once in awhile. Do I need to clean something inside or you think a part is going bad? Thanks Rambozo and everyone!

Looks like I took too long to suggest that. ;)

Glad to hear you are up and running, again.

I still wonder about the positive half of the wave. The HF runs until it detects the main arc is stable. I don't know the exact circuit and if it checks both positive and negative portions. Older machines will let you run the HF continuously, so it should have welded even if the HF was stuck on. My guess is that there was no positive side of the main arc or it was intermittent or something. You would have to see the output on a scope to be sure. I would keep an eye on it and let tech support know about this, anyway.

If yours is a points machine ( they changed a few times) , it never hurts to clean and adjust the HF points. Good time to blow out any dust inside, too.
Because of the dirty shop environment, it often helps to flip all the switches and turn all the knobs from time to time to help clean contacts and such. Especially if the machine isn't used all the time.