ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
Check that POWER ON light is on
Set MODE SELECT switch to VENT
Check that CIRCULATE light is on.
Check that the following lights are off:
HIGH DISC PRESSURE,
LOW SUC PRESSURE, and
If any light (except POWER ON and CIRCULATE) Is on, turn MODE SELECT
switch to OFF. Contact unit maintenance
Perform "during operation" preventive maintenance checks and services (table 2-1).