ARMY TM 9-6115-670-14&P 5-50 5.18.  RELAY BOARD. This task covers:     a. Inspect b. Replace INITIAL SETUP Tools General Mechanic's Tool Kit (Item 1, Appendix B) Materials/Parts Relay Board 10 Amp Fuse 5 Amp Fuse (2) Equipment Conditions MASTER ON-OFF switch on APU control unit set to OFF. Air filter removed (para 4.45.). INSPECT a.  Remove four screws (JTACS), or slotted hex-head bolts (SICPS and WIN-T), flat and lock washers (1, Figure 5-12) and remove generator housing top cover (2). b.  Remove four screws (JTACS), or slotted hex-head bolts (SICPS and WIN-T), flat and lock washers (5) and generator housing side cover (4). c.  Inspect fuses F1, F2, and F3 (7) on relay board (6). d.  Replace blown fuses (7). REPLACE a.  Remove four screws (JTACS), or slotted hex-head bolts (SICPS and WIN-T), flat and lock washers (1), and generator housing top cover (2). b.  Remove four screws (JTACS), or slotted hex-head bolts (SICPS and WIN-T), flat and lock washers (5), and generator housing side cover (4). c.  Refer to foldout F0-1 (SICPS/WIN-T) or F0-7 (JTACS) and tag and remove electrical leads from relay board (6). d.  Remove six nuts with captive washers (8) (JTACS) securing relay board (6) to vibration mounts (3), or six screws, flat washers, lock washers, vibration mounts, and hex nuts (SICPS and WIN- T) and remove relay board (6). WARNING Ensure that APU DC power supply is disconnected.   Failure to observe this warning could result in severe injury or DEATH to personnel. WARNING Ensure that the APU is turned off and completely de- energized    before    opening    generator    housing.   Failure to observe this warning could result in severe injury or DEATH to personnel.