Need Help! Mori Seiki SL3 spindle alarm

Fanuc 5T Spindle problem

I have a Mori Seiki SL3 lathe fitted with a Fanuc 5T control
Today my ready light comes on but my spindle motor will not start and a PCB alarm SAI cones on in PCB A20B-0004-0990/03A. What is an FAI alarm?

The fault appears to be -15V supply is less than 1Volt?

My machine is fitted with a model 12 DC spindle motor (11kW).

The spindle drive cabinet has the following PCB visible
A20B-0004 -0990/03A
A20B-0005-0610/05A

There are no manuals for the spindle drive part of the machine.
I measured the following voltages

(a) Main fuses F4(212V), F5(212V), F6(212V)
Same voltage top and bottom of the fuses.

(b) Incoming supply R1(212V), S1(212V), T1(212V)
(c) Incoming supply R0(440V), S0(444V), T0(440V)

(d) Measured the following voltages on PCB A20B-0004-0990/03A.
24V test point measures 30V
15V test point measures 14.7V
-15V test point measures 0V

My question is where is the -15V voltage regulator?
How do I adjust the 24V test point?

The power unit for this machine is FANUC A14B-0046-B00V01.

I am most grateful for any assistance.
If available where can I purchase manual for my Fanuc model 12 spindle drive?

Best regards Woofa