I have problem with Fanuc OMD-II
error code: 420 & 421 (excessive position error during stop/move)
Accoding to the maintenance manual # B-62545 EN/02 proposed action have taken as follows:
• Checked parameters 517, 593 to 596, 549, 650, 7593 & 7594 and found OK.
• However, according to downloaded list (back up) before error/ this problem parameter # 7593 cannot be seen in parameter list.
• Checked power supply at motor terminals and found ok while axis was stationary.
• Checked power supply at servoamplifierwhile moving axis by jog mode, pulse generator and rapid and even zero return found no voltage.
• Checked cables between Axis card and servo amplifier found ok.

Present condition of Axis:

Sometimes axis moves but with jerks and no error shown/occur. Most of the times error occurs and moves not and motor spindle vibrates continuously, showing fluctuation of power.

Need help in this connection. thanks