TM-9-2350-274-BD M109 Battlefield Damage Assessment and Repair Download
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TM 9-2350-274-BD COMMUNICATIONS SYSTEM 11-6. OBSERVABLE SYMPTOM: THE INTERCOM DOES NOT WORK ON ANY CONTROL BOX Detailed Assessment Steps: ■ 1. Check that the DC power is available to the turret by checking the dome light or other electrical equipment in the turret. ■ 2. Check that the MX-7777 or MX-7778 Transient Voltage Suppressors operational by depressing the Battle-Override switch. If the suppressor is bad, replace or repair as necessary. 3. Check that communication equipment is turned on and the switches are in the proper positions. (Refer to para. 11-4.) 4. Check that cables are connected to the proper connectors, correctly aligned, and tightly connected to the receptacles. 5. Jiggle the cables to check for intermittent opens or shorts. a. If a defective cable is found, follow the procedures listed below: (1) Replace the defective cable in accordance with standard repair procedures. (2) Replace the defective cable with an acceptable replacement cable (refer to para. 11-16). (3) Repair the defective cable in accordance with the repair procedures in para. 11-12, or the electrical chapter of TM 9-2350-276-BD. b. If a defective cable is not found, then follow the troubleshooting procedures in TM 11-5820-401-12. 11-7. OBSERVABLE SYMPTOM: THE INTERCOM WORKS ON SOME CONTROL BOXES BUT NOT ALL Detailed Assessment Steps 1. Repeat steps 3 thru 5 in para. 11-6. 2. Replace CVC helmet and connecting cable with a known operational CVC helmet and connecting cable. a. If the problem no longer exists, no further action is necessary. b. If the problem has not been corrected, go to step 3. 11-6 Change 3