Fanuc 0m-a no spindle control

Hello all, I have a knockoff brand bed mill (Long Chang Machinery RB-1) with a Fanuc 0m-a CNC.
Up until last week when I finished manually facing off a piece of aluminum, I stopped the spindle like I always do... Then I went to turn it back on (MDI mode -> spindle cw button), and nothing.
Lights don't change, diagnostics bits pick up the button presses, but they don't do anything.
Any calls to m3/m4 just hang the program and MDI until you hit reset.

I'm assuming there's a limit or something that needs to be met, but there aren't any on the spindle (only the typical axis switches).

I've checked all the relays and wires, but I don't have any schematics for this thing either.

Anyone have any ideas? I don't need the machine right now, but I'm sure I will soon.

Edit:
Oh and its just a basic spindle, not a servo driven unit, so the CNC only controls a reversing contactor.

If M03 hangs a condition needed to allow it is not right. Can you get into the ladder?

No, from everything I've read, the ladder is not displayable on this model unless you pull the PROM chips and have the decoding software (I have equipment to read the PROM chips, but no way to decode them).
I couldn't find any info on the ladders by google search either.

That makes this a hard nut to crack. I would look at the tool clamp switch.

See that's what I don't get... There aren't any other switches than the axis limits and one switch on hi/low gear change (to reverse cw/ccw), but other than that I don't see anything.

I've been digging through the wires and it also seems that it won't turn on the coolant pump either, of which the relays have power and I can engage them manually... So it seems the CNC output just isn't switching the output.
Which brings me back to software issues or limits not met.

WIl the people you bought it from have any information?

No unfortunately, they've passed on from what I know... That's why I have the machine (auction).

Is there a document that explains the inputs/outputs on the controller, along with the diagnostic bits?

inputs/outputs on the controller, along with the diagnostic bits must come from the builder of the machine.

Is there a document that explains the inputs/outputs on the controller, along with the diagnostic bits?
The builder designs all that. The control is a blank slate, untill the bullder loads the software that they have designed for that machine.

what kind of eeproms with ladder on your CNC - 27C64 or 27C256?

64.
The front panel is labeled "General Numeric GN0".

Its nearly identical to this one on eBay:
https://www.google.com/url?sa=t&rct=...80185997,d.eXY

for 27C256 you can use FAPT ladder under DOS for decompiling, but 64 - not

Well, I think I found a solution...
While fiddling around with M3/M4 in MDI, I found that it only hangs until one of the relays for the spindle pull in, so that got me thinking...
Then while fiddling with M3/M4 a little more while watching the output bits (#45 & #46 I think) in the diagnostic params, I noticed that there were two different bits that followed M3 and M4.
So with M3/M4 hanging, I probed the extra output wires and found the two that matched the bits I saw in diagnostics.

I didn't have enough time today to rewire it today, so it will have to wait until Monday to find out for sure, but here's hoping!
I get the feeling that M3/M4 will work, but I won't be able to engage the spindle with the CW/CCW buttons.

The big question is, why did this happen?

at least try to find diagnostics bits that correspond to buttons, maybe there is lack of 24V