TM9-4120-400-14
TROUBLESHOOTING - continued
Table 4-2.
MALFUNCTION
TEST OR INSPECTION
C O R R E C T I V E ACTION
EXCESSIVE NOISE.
Step 1. Check evaporator or condenser fan for vibration.
Tighten fans on shafts. Tighten all mounting screws.
Step 2. Check evaporator or condenser fan motor for wear, as indicated by noisy operation or excessive
side or end play. (See para 4-41 and 4-44.)
Replace worn or bad motor.
Step 3. Listen for compressor knocks or chatter.
Stop air conditioner and notify supervisor.
Section VI UNIT MAINTENANCE PROCEDURES
GENERAL.
The procedures in this section have been arranged in the order in which the items appear in the unit (0)
maintenance level column on the Maintenance Allocation Chart (MAC) which is provided in Appendix B. Step-by-
step procedures have been provided for all action authorized to be performed by unit maintenance in the order in
which they appear on the MAC.
