Quote Originally Posted by JSMachining View Post
Looking for a starting point with a Hitachi HT20. At start up I'm getting alarms.

392 Z-axis Disconnect
390 Servo Pack Alarm
310 Power for servo not supplied

It will allow me to hit the standby button but about 2 seconds later it kicks out and then nothing works.

Any help would be appreciated.
After doing the checks recommended by the previous poster, power down machine, lock it off and remove the drive. Take it to your nearest specialist drive repair center (Fanuc?).

If it were X or Y axis you could swap them to see if the fault moved with the drive.

Z axis is usually a bigger more powerful drive and on a vertical machine often has a brake circuit. (Probably not in your case).

I suspect drive transistor fault or power supply.