DESCRIPTION

TM 11-6625-3081-23 7-15. INDIRECT VIEW DISPLAY (IVD) 2A1A3 WITH OSA 7-15 INPUT CODE: IVDST a . DESCRIPTION This module tests the ability of the indirect view display (IVD) 2A1A3 to produce correct outputs in response to function commands. An error detected during any of the following checks will display a prompt at the completion of the test. The optical signal analyzer (OSA) chassis to shield continuity is checked for 10 ohms or less. The OSA shutter interlock operation is verified by checking the shutter status with the OSA door open (shutter closed). The operator closes the OSA door, the shutter is programmed open, and shutter status checked. The internal and external relays 1 through 4, phase A, B, and C contacts are checked for a closed condition. The operator opens the OSA door and the OSA shutter is checked for a closed status. The internal and external relays 1 through 4, phase A, B, and C contacts are checked for an open status. The operator applies pressure to OSA door interlock switch S1 while OSA door interlock switch S2 is checked for a shorted condition. The operator then releases S1 and applies pressure to S2 while S1 is checked for a shorted condition. The operator then releases S2 and closes the OSA door. The OSA door status is checked. The IVD is then programmed to produce a vertical output pulse and a horizontal output pulse, which are checked for period and amplitude. b . REPLACEMENT PROCEDURE REFERENCE The following list provides a cross reference of replacement items to replacement procedures. The item column identifies the item to be replaced by reference designation and part number. The reference column identifies the procedural paragraph used to perform the replacement action. The VDT screen will display the proper sequence of repair/replace actions. Item (Ref Des/Part No.) Reference (Para No.) 2A1A3/13078701 5-25 7-65