Tonight I was searching for information regarding high frequency intensity and came across several posts on this site
Larry and Henry seemed to have the most input on several posts and I am sad to find out that Henry is no longer here
I was looking forward to speaking with him on general knowledge of my subject manner among other topics, so I asked to join
That had to be a sad day for all of you that knew him
Onto my situation, I have owned this machine for close to 20 years and it developed an issue on the high frequency side shortly after I purchased it
It has sat in the corner most of the time here until a couple of weeks ago, and I am determined to get it working correctly
I do not know the serial number but a good share of the parts have tags starting with the letters JD
When the machine is first turned on, I can set the HF to start and weld dc for about 20 minutes before the HF arc begins to become weaker and finally goes away
The CR1 and CR 2 relays points were rather cooked, so I purchased a replacement for the CR2 and bought a new Midtex relay for the points to rebuild the old one since this relay is no longer available
This machine has had countless issues with these two relays for years, and the Internet is flooded with posts regarding HF issues
As I was in the process of changing the points, I noticed an amount of silver looking dust on my fingers
Looking closer to see where this was coming from, I noticed two areas on the boards inside this voltage sensing relay that had dark spots
The material that was used to make the circuitry, was actually missing in these two areas and a good share of the remaining runs were rubbing off onto my fingers
I figured I had nothing to loose now, so using a magnifying lens I was able to see the paths and using copper foil adhesive backed tape, I rebuilt the missing runs and ran solder over ever run
I searched for a schematic with no luck, but each matching set of contacts do have resistance
I had narrowed the problem down to being the HF transformer or the HF capacitors before coming across this issue
I just pulled the copper straps off the capacitors tonight and all three have zero capacity
These list for around 180.00 each and that might not be a total fix, so I went searching for capacitors
I found a person on eBay that designs and builds a HF conversion unit for stick welders for under 100 dollars that uses only one capacitor and one set of points with new components
He has looked at the schematics for my machine and guarantees that his unit will work with the intensity pot and connect to the primary and secondary leads of the transformer, which he claims would not interfere with the circuitry
I’m also digging in my stash of capacitors hoping to find something that might be even better than the .002uf 5,000 vdc units it came with
Any comments would be appreciated and I also have an inverter mig welder from a robotic station that had pulse and a water cooled stinger for parts