Next Generation Control control machines equipped with a 60A servo amplifier  alarm 991 AXIS AMPLIFIER OVER TEMPERATURE can erroneously be generated.
- Install a ferrite filter (P/N 64-1252) to the axis motor power cables .
- If the machine has the ferrite filter installed and the alarm persist replace the 60A servo amplifier with (P/N 93-32-5552F or later).
- If the machine already has the 60A servo amplifier (P/N 32-5552F or later), check the amplifier PCB serial number. Look through the amplifier vent slots, if the serial number starts with "NT", replace the amplifier with the 93-32-5552F or later (All 60A amplifiers with the serial number "NT" have been purged from stock).
Also check for a real overheat condition. Look at the servo fan for correct operation and the cutting application before changing any parts.