TM  11-5820-890-20-2 3-3 3.1. OPERATIONAL CHECK. Continued STEP 4.    CM FUNCTIONAL CHECKS: STEPS TO PERFORM CHECKS TO MAKE ACTIONS TO TAKE 4.1 Set CM FCTN to RF Observe displays Control •M" lit? YES:    Continue NO: Replace CM * All displays correct? YES:    Go to Step 4.2 NO: Go to TS Chart 3 4.2 Press INIT up and release RF •M" lit? YES:    Go to Step 4.3 NO: Replace CM 4.3 Set FCTN to CHAN; INIT up and release CHAN display reads •1"? YES:    Go to Step 4.4 NO: Replace CM 4.4 Set FCTN to RT MODE; INIT up and release MODE display reads •FH"? YES:    Go to Step 4.5 NO: Replace CM 4.5 Set FCTN to COMSEC; INIT up and release COMSEC display reads •CT"? YES:    Go to Step 4.6 NO: Replace CM 4.6 Set FCTN to VAR; INIT up and release VAR display reads •2"? YES:    Continue NO: Replace CM RADIO 2/3 present? NO: Continue YES:    Go to Step 4.7 Another CM present? YES:    Run STEPS 3 and 4  for 2nd CM NO: STOP,  OPERATIONAL CHECK COMPLETE 4.7 Set RADIO to 2/3; set CM to dis play messages (below) Rerun Steps 4.1 - 4.6 END OF OPERATIONAL CHECK *  NOTE: Display Message RF LO RT MODE SC CHAN 0 VAR (blank) COMSEC PT