TM 1-1520-238-T-4 6–136 Change 1 6–63. OIL HOT NOSE GRBX 1 INDICATOR – IS LIGHTED WHEN HOD DISPLAYS HIGH NGB 1 6–63 OIL TEMPERATURE Tools: Nomenclature Part Number Tool Kit, Electrical SC518099CLA06 Repairer’s Tool Kit, Powertrain SC518099CLA013 Repairer’s Multimeter, Digital AN/PSM-45 Personnel Required: 68D Aircraft Powertrain Repairer/NDI 68X Armament/Electrical Systems Repairer 152FG Maintenance Test Pilot References: TM 1-1520-238-T-6 TM 1-1520-238-23 TM 1-1520-238-CL Equipment Conditions: Ref Condition TM 1-1520-238-23 Access provisions – L200 access panel and LN6 fairing open WARNING Turn off power before detaching or attaching wires and connectors. High current 28 VDC or 115 VAC is present. Failure to do so could result in death or serious injury. 1. Check HOD display for NGB 1 oil pressure reading. Is oil reading 28 LB or lower? YES Go to paragraph 6–62 to troubleshoot OIL HOT NOSE GRBX 1 indicator. NO Go to step 2. 2. Check pilot caution/warning panel OIL PSI NOSE GRBX 1 indicator. Is indicator lighted? YES Go to paragraph 6–60.1 to troubleshoot HOD NGB 1 display. NO Go to step 3. 3. Check HOD display for NGB 1 oil temperature reading. Is oil temperature 121 C or higher? YES Go to step 6. NO Go to step 4. 4. Detach P18. Does indicator remain lighted? YES Refer to TM 1-1520-238-T-6 to troubleshoot the pilot caution/warning system. NO Go to step 5. 5. Check for short between J61–A and P18–52. Does short exist? YES Repair shorted wire. Go to paragraph 6–13. NO Replace NGB 1 metallic chip detector (TM 1-1520-238-23). 6. Inspect NGB 1 for cooling fin blockage (TM 1-1520-238-23). Is there blockage? YES Clear fin blockage and correct damage (TM 1-1520-238-23). NO Go to step 7. 7. Check NGB 1 flexible coupling shaft and fan (TM 1-1520-238-23). Is fan blocked or damaged? YES Clear fan blockage and correct damage (TM 1-1520-238-23). NO Replace NGB 1 lube pump (TM 1-1520-238-23). END OF TASK