So you're saying that X did Zero Return? (Nothing said about X axis)

Yes no batteries or they would be plugged into CX5X where the little brown plastic thing is. Your control WILL have a battery somewhere. That's the most important one to change on any machine.

Back up a little from the Servo Amp pictures you took so we can see the whole thing. Also their part numbers (A06B-xxxx-xxxx) Also how about another shot or two of the control panel's bottom two panels. They may come in handy sometime if I'm trying to help you past a problem or something.

Yes this machine will need to be zero returned each time you turn it on. My OM is like that too. No big deal. As you noticed, each axis will travel at a Rapid Rate until it hits the first Deceleration Dog. From there it will slow until it falls off the back end of that Dog and then start counting the Grid and stop at Home. The Grid Shift amount held in parameter 1850 in concert with the Dog controls where the machine stops. There is really no reason they would need changing. That's one of the good things about Incremental Machines. The Servos don't use batteries so they can't loose their home position. It's set semi-mechanically using Trip Dogs and Grid Shift.

A heads up - whenever you get a Servo or Spindle Alarm of some kind, (Not sure if overtravel alarms are part of this) you might get a number and brief description on the screen, but there may also be a number that shows up on the actual amplifier inside the main cabinet. That number can be helpful too. It will be a Fanuc Alarm number where you can Google it. The one on your monitor screen will likely be a Miyano alarm number. You may get lucky Google-ing it but one never knows. That's why it is so important to have the manuals.

Not sure why it's not Zero Returning Properly. Did you just have to hit the plus button(s) once or hold them in? You can Zero Return the axis in any order. If you do overtravel and get an alarm, you can go into Handle or Jog Mode and simply move the axis axis back in the opposite direction and then hit Reset which should clear the Overtravel. Remember on your machine, get into the habit of moving all the axis at least a couple-few inches away from home position, even to middle of travel if you want. After turning the machine on, you don't want to try and Zero Return with the axis already on top of the Trip Dogs.

As a last resort, if you're consistently getting an overtravel on all axis when trying to Zero Return, turn on the Fanuc control while holding in P and Cancel (CAN) together until the control comes up. Very important. DO NOT HOLD ANY OTHER KEYS. Then try your Zero Return again. Maybe slow the Rapid Rate down to the 25% setting if you have one. P and Cancel will clear some things in the control and allow the Home Position Zero Return stuff to be reset. There are other key combinations that will clear about everything on the control, that's why it's important to not mess that up.

It will be great when you get it up and Zero Returned. Then you'll know it's ready for action and can forget about all this technical nonsense and just start concentrating on learning to program it. Hopefully it has no serious underlying problems.