Mori Seiki SL1 Servo error

I have a Mori Seiki SL1 with Yasnac 2000G control. Went to power up today and got an error 31, servo power unsupplied. Checked the DC power supply and saw that the 6 leds were not lit. When I power up the machine, error lights 2,3 and 6 on the circuit board flash briefly then go out. Checked the thyristors on the PS and they are all ok. Any one have suggestions? Thanks