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.
Hi All
I wish to report the machine is up and running.
My Spindle Servo Unit is Model-12
Fujitsu Fanuc
SP-5/10
A06B-6041-C002
No SS10193
The LHS PCB A20B-0004-0990 has a 15V regulator uA7815 all the regulators on this PCB measured OK and they do not appear to be the supplies for PCB A20B-0005-610.
The PCB underneath is A20B-0005-0583 also has regulated supplies and supplies power to the top PCB via the ribbon connector cable.
I replaced the faulty regulators UA7815 and UA7915 and all the voltages measured OK, no alarm.
My Mori is up and running. A service/maintenance manual would have saved a lot of time.