Hi, I have a Jasic 200 AC/DC TIG I borrowed from a friend for welding aluminium, it was working fine then one day it made a pop noise, so I pulled it apart and found one of the boards had burnt, so I ordered a new board (PN-07-A2 which is now updated to PN-07-A3) and replaced it on the unit. Now the unit turns on with no issues and swaps between AC and DC mode, but I have an issue where the gas doesn't actuate when the trigger is pushed on the hand piece. So I pulled out the solenoid and replaced it with one from a working machine and put the one from the Jasic into this other machine and it worked fine, so the solenoid is not the issue.
Then I replaced the handpiece because I thought it may not be sending the signal to open the solenoid, this wasn't the issue either. The new handpiece does the exact same thing, HF actuates but no gas, I can get an arc but it just destroys the tungsten because it has no gas shield. I have taken it to 3 people who sell/repair units (here in AUS) and they have just said "they aren't worth fixing" without even having a look, because it is made in China and they could spend hours working on them and you can buy a new one for $1,800.00 AUD. They expect if they tell you they can't fix it, then you'll just go ahead and buy a new one off them!!! My issue is I borrowed it off a friend and I want to fix it for him, without having to spend $1,800.00 AUD on a new unit.
I'm out of ideas on what can be causing this, I have a multimeter and have been checking everything without luck, the solenoid works on the other machines as does the handpiece. I have a schematic drawing and photos but I'm struggling to work it out and would greatly appreciate any help you may be able to give.
Then I replaced the handpiece because I thought it may not be sending the signal to open the solenoid, this wasn't the issue either. The new handpiece does the exact same thing, HF actuates but no gas, I can get an arc but it just destroys the tungsten because it has no gas shield. I have taken it to 3 people who sell/repair units (here in AUS) and they have just said "they aren't worth fixing" without even having a look, because it is made in China and they could spend hours working on them and you can buy a new one for $1,800.00 AUD. They expect if they tell you they can't fix it, then you'll just go ahead and buy a new one off them!!! My issue is I borrowed it off a friend and I want to fix it for him, without having to spend $1,800.00 AUD on a new unit.
I'm out of ideas on what can be causing this, I have a multimeter and have been checking everything without luck, the solenoid works on the other machines as does the handpiece. I have a schematic drawing and photos but I'm struggling to work it out and would greatly appreciate any help you may be able to give.