Micromill 2000 NS "Z" not homing

[boots]

Micromill 2000NS
S/N u00634/4
Elect. u0610090012
Oct. 2006

Z will not home, just moves slowly down. Used VR Milling v2.31(RS-232) and v5.13(RS-232 & USB). Windows XP.
False homed machine, Z axis jogs perfectly.

Check and replaced the home switch.
Checked connections on control card.
Checked continuity of wires from card to switch.
Moved "ground" lead to different ground connector.

This machine was working fine a couple months ago, X & Y work perfectly.

Anything else to check?

[Denford Admin]

If the switch and wiring is fine, then I'm guessing that the home input has blown.

You can try the latest EasyUpgrader which now has I/O monitoring functions (you will have to email me to get the password)
That way you can connect a test button and wire straight to the Z home input and see if the button changes the input state.

[boots]

Installed a new NextMove card - works great.

Installed original top card on new bottom card - same problem, Z will not home.

Installed new top card on original bottom card - machine works great.

Problem is in the top card, anyway to correct this?

[Steve]

Sounds like the input chip is shot It will require returning for repair.

[boots]

OK. We'll send it back.