[Myk Bates]

I am hoping someone here can help me with some trouble shooting. I recently got a 1987 Fadal VMC40. The guy I got it from bought it from the place he worked to start making parts on the side but could not get three phase at the house and finally decided to get rid of it. It was a working machine when he bought it. The machine was in a guys garage for about a year I think, and he had removed the Z axis servo to get it through the door. When I got it to my shop I re installed the servo and wired it up. I powered it up and entered 2 for the pulley set up. The next screen tells me to jog to Home positions and then enter CS (cold start command) so I press the JOG button on the keyboard. It momentarily displays "JZ" and then "Amplifier Fault on Axis Z". I swapped what I think is the X and Z axis amps by moving all the wires on the two outside amps but I get the exact same error. I then reconnected the drives the original way and removed the power (black and red) wires that go to the Z axis servo and tried again only to get the same error. It is peculiar to me that it faults on the axis that the motor was removed. But it seems that the controller stops there and for all I know the controller has not checked the X or Y amp and I may get the same error there once I move pass the Z Axis Fault error.

The Fault lamp on the drive is not lit up and I am wondering how else to trouble shoot this before I start throwing money at parts to find out which one is bad. Any ideas here? Has anyone else had a similar problem?

[jon_fallon]

Can you move the z-ball screw by hand?

For transport, there are rods in the back to hold the counter-weights in position. Were they installed during the transport?

-jbj

[Myk Bates]

Yes the ball screw turns by hand. Since my first post I found the wrong size fuse in the Z axis amp (15 instead of 20) and the wrong relay next to fuse 14 That is what lets power go to the drives. It was 300mA instead of 3Amp. I swapped it with another one and got power to the drives. I have also noticed some wire straps that have been removed. Apparently someone has been trying to fix this machine already. Next the problem became the Z axis motor taking off and then faulting as soon as it got power. (The motor is disconnected from the machine) The X axis did the same thing but did not fault so I have it electrically disconnected for now till I get the Z taken care of. I got some good trouble shooting tips from FadalCNC.com and have been working through one suggestion after another. They have been a great help and most of this trouble shooting has been from them and not my ideas. There are four wire combinations with the Tach and the motor leads. If the wiring is wrong it will cause the motor to run off like it did. I tried all four combinations last night but got the same result. However when I unplugged the resolver the motor will run like it did before but not fault. Now I have to determine if that is a wiring issue, a resolver problem, a motor problem, or all of the above.

[kheston]

This was the only thread I found with the error "amplifier fault on axis Z" that I was seeing on my 1993 Fadal 3016. But, my fix was different, so I thought I'd share.

The z-axis was fine prior to transport, but wasn't working when I got everything connected in my shop. Thankfully, after re-seating my axis controller cards/connections, the problem went away.