Hi All,
New to post here but have visited often since buying my 06 FX4 SCREW.
There seems to be a knowledgable bunch here regarding welding, so I have a question.
I have a Miller Blue Star 6000 gas powered welder that has developed a problem. The amp setting does not seem to make any difference regardless of the setting. The machine seems to run very high amps even with it set to the lowest setting. There is no change from highest to lowest settings on the dial, it just melts the rods and the engine bogs down hard whenever I strike an arc. The machine was purchased new in '98 and has less than 100 hours on it. Any suggestions on where to start looking before I try to locate a service center?
For what it is worth, about 40 of the hours were put on using it as a generator during hurricane Rita last year to run the freezer and such. The problem started after that as far as I can tell.
Thanks

 

If it has the auto idle, make sure that is turned off or to the weld position.
I would recommend checking the amp output with a clip-on ammeter, they have some at Lowes for around $30, should be accurate enough for this.

 

Well, as much as I hate to tell you, the most likely problem is the control board. There are, however, a few other possibilities. The fact that it's stuck at maximum output is a far more rare problem than having no output or minimum output. I don't know how electronics savvy you are, or if you even own a multimeter, but I'll tell you a couple of things to check. Maybe you have a friend who could check them for you if you don't feel comfortable with it. Before that, even, I'd suggest opening up the case and give it a good visual inspection. There is a small shunt mounted to the inside bottom of the case. It'll look like a block with two cables attached and two small wires leading from it to the board. Make sure the two small wires aren't broken or corroded. Look at the terminals inside the connector to the board for corrosion as well. Do the same for a small wire (number 17, I believe) leading from the board to the reactor(big transformer-looking thing). Last, look at the wiring from the potentiometer(heat control) to the board, and/or check it with an ohmmeter. Hope some of this helps. If you or someone you know is competent to do some more in-depth troubleshooting, e-mail me and I'll send you a PDF file of the service manual. Welcome to FTE!

 

Thanks for the great info. While I'm certainly no electronics guru, I have all the basic tools to do some checking. I'll open it up and check what you recommended first.
By the way ford_six, no auto idle on this model machine and I'll check the amps but I'm pretty sure they are stuck at a const and high output.
Thanks again.

 

Only the DX machines have auto idle. Will a clamp on meter work on a DC machine?