Fanuc 21i 401 Sevo Alarm Axis Vrdy Off Fault

Hello, I have a Fanuc 21i on a Daewoo 5025 vertical machining center.

On power up I get 401 vrdy alarm on all 3 axis.
In trouble shooting it, I replaced the CNC axis control PCB A20B33000392 per a Fanuc tech but it did not fix the problem.

I disabled the Z-axis in the control by changing a few parameters and the problem went away.

12 bit 7=1;
1005 bit 7=1;
1023=-128;
2009 bit 0 =1

Coincidence or can I be confident the problem exists with the Z-axis some how?

I had had the z-axis drive cleaned and tested; all was good.

Could it be the Pulse Encoder A860-2005-T310 or would that give me a different fault? How can I be sure if the encoders cable is making good connections on all the pins?

Could the motor be bad A06B-0253-B401?

What's the likelihood it might be the main PCB board the axis control card gets plugged into?

Open for suggestions.

Thanks,

Russ