It may be the death of me but..... fanuc11 Z velocity drive kicking out on startup

I aint giving up!!!
Z velocity drive on power up engages and then disengages.
ohm check wires, removed and checked servo, swapped drives, and few hundred other things so far but.... still.. main servo relay jumps in and jumps out within seconds. maybe its the dro?

I have came to the overall conclusion that that is what is causing several issues I am experiencing.

anybody know anything about what I described?
God Bless You all who respond and have been trying to help me.

Is there an alarm led on the drive circuit lit up? If so, post that. If not then the PLC may be dropping the power to the servo. Do you have a wiring diagram and copy of the ladder logic? Is this machine using the Fanuc PLC or a 3rd party?

Im sorry, i dont know what ladder logic is but I am Using the attached fanuc plc. I do have a wire schematic and everything looks like it should be and original with factory tags. No reds on. 2 greens glowing, 100v at 3 & 4 like fanuc says. SV013 alarm on Z . Traced wires all the way to servo and ohm checked. If i take wires off here and there on the drive like to the servo or power in I get codes related so it seems all wiring is good. I didnt check from transformer to drive 3 wires. Assuming thise are 3phase in to charge capicitors or something.
Thought for sure was just a bad drive but no luck.

I even bench tested the servo motor. Smooth and quiet.

I know you've been through a lot with this and almost certainly you've double checked the simple stuff.. but is the Z on an overtravel switch?

Can you press "CON" with the emergency reset button pressed and then jog the Z?

I seem to remember my Fanuc 11T will throw SV013 if it's on the hard switch on either axis, and the solution wasn't immediately clear when I first got the machine.

Thank you.
I dont have a con key that I am aware of. I have manually moved Z off and on travel switches. It has 2. 1 to slow or tell it its about to hit and the other to actually stop it.
I have ohm checked those and they seem to be in good working order.
I am starting to suspect the PLC has some issues but no clue where to start on diagnostics on it. The Z "quil" lead and ball are smooth and look in above average conditions.
This machine is new to me and I was told it was operational at time of decommissioning. For its age it appears to have been well maintained and documentation showing repairs and maintenance.
During unloading it was dropped and damage was limited to cosmetic but included X servo replacement. Behind the CRT we found 2 plugs had also came unplugged but plugged them in and she lit right up.
I feel at this pint it may not be any mechanical issue and may be PLC fault/s....

Try starting the control with the emergency button pressed - if the drive powers up and you can jog, it's likely a limit switch issue (broken switch, broken wire, something screwy on the main board or something).

Good advice, I didnt ohm limit swith wires back to anything...Will try it for sure Monday.
What main board are you referring to?

I don't actually know a lot about Fanuc systems so it was more of a generic possibility than anything.. pretty sure the Fanuc controls have a main board that controls everything and in the worst case maybe something on there could be blown, perhaps? Anyways it could be some board-level fault, possibly.

Well Sir, I certainly appreciate your good advice and will follow up after I get a chance to check it.

I have a picture of the inside electronics but working off my phone cant find a place to add a picture.