How do I check and set the axis amperage?

The axis amperage is checked by replacing the axis fuse with a DC ammeter. You will need a meter with at least a 10 amp DC range.

FU 14 is the Z axis fuse (Wire 28), FU 13 is the Y axis fuse (Wire 26) and FU 12 is the X axis fuse (Wire 24) and they are left to right 14, 13 then 12 (check the wire numbers).

The amperage is adjusted with the trim pots on the edge of the ACC card. Z is controlled by the bottom one, Y by the center one and X by the top one.

Do NOT connect or disconnect the meter while the axes are powered up.

Is there an easy way to check the bridge rectifiers?

With the power to the machine off, connect the red lead of the digital multi tester set to the diode test function to a terminal number 39 on the machine. Connect the black lead to the following wire terminals one at a time, #11 and #20 for the X axis rectifier, #13 and #21 are for Y, #15 and #22 for Z . The meter should read .5 to .7 between terminal 39 and each of the above wires. You have just checked the negative half of the bridge rectifiers.

One of the axes makes noise but does not move. What is wrong?

While watching the mechanical counter for that axis, repeatedly single step the axis. If the counter steps once or twice and then jumps backwards, you have a bad power transistor on the driver block for that axis. If more than one transistor is bad, the counter may not move or it may just wiggle.