190-00325-02 september 2009 revision a gma 347 audio panel maintenance manual.
_________________________________________________________________ i copyright 2009 garmin ltd. Or its subsidiaries all rights reserved except as expressly provided below, no part of this manual may be reproduced, copied, transmitted, disseminated, downloaded or stored in any storage medium, for any ...
_________________________________________________________________ ii blank page.
_________________________________________________________________ iii contents section 1—introduction 1.1 model designation ......................................................................................... 1‐1 1.2 maintenance concept .............................................................
_________________________________________________________________ iv section 4—repair 4.1 tools ............................................................................................................... 4‐1 4.2 disassembly and assembly ..............................................................
_________________________________________________________________ v warnings, cautions, and notes warning this product, its packaging, and its components contain chemicals known to the state of california to cause cancer, birth defects, or reproductive harm. This notice is being provided in accordan...
_________________________________________________________________ vi warranty information this garmin product is warranted to be free from defects in materials or workmanship for one year from the date of purchase. Within this period, garmin will, at its sole option, repair or replace any components...
_________________________________________________________________ section 1 introduction this manual contains repair information for the gma 347 audio panel/marker beacon receiver. Unit description, theory of operation, troubleshooting, testing, and replacement procedures are included. Installation ...
_________________________________________________________________ page 1‐2 gma 347 maintenance manual rev.A 190‐00325‐02 1.2 maintenance concept the maintenance concept for the gma 347 is to fault isolate down to board level and return the audio panel to operating condition. There is no component le...
_________________________________________________________________ gma 347 maintenance manual page 1‐3 190‐00325‐02 rev. A 1.4 service bulletins service bulletins may be issued on product for either software or hardware changes. The service bulletin will indicate if the change can be made in the fiel...
_________________________________________________________________ page 1‐4 gma 347 maintenance manual rev.A 190‐00325‐02 blank page.
_________________________________________________________________ gma 347 maintenance manual page 2‐1 190‐00325‐02 rev. A section 2 audio panel description the gma 347 is a horizontally oriented, panel‐mounted audio control panel and marker beacon system. Microcontroller circuitry processes front pa...
_________________________________________________________________ page 2‐2 gma 347 maintenance manual rev. A 190‐00325‐02 2.1.5 music 1 and music 2 controls the audio panel provides two stereo auxiliary entertainment inputs; music 1 and music 2. These inputs are compatible with popular portable ente...
_________________________________________________________________ 2.2 audio panel controls figure 2‐1. Gma 347 front panel 1. Marker beacon lamps 2. Manual squelch indicator led 3. Marker beacon receiver audio select/mute button 4. Transceiver audio selector buttons (com 1, com 2, com 3) 5. Photocel...
_________________________________________________________________ page 2‐4 gma 347 maintenance manual rev. A 190‐00325‐02 15. Pawl‐latch access 16. Transmitter (audio/mic) selection buttons 17. Marker beacon receiver sensitivity 18. Pilot ics voice activated transmission (vox) intercom squelch level...
_________________________________________________________________ 2.3 theory of operation the audio panel contains three major replaceable assemblies: • main board assembly • audio board assembly • front panel board assembly the three major assemblies are shown in the block diagram in figure 2‐2. Fi...
_________________________________________________________________ page 2‐6 gma 347 maintenance manual rev. A 190‐00325‐02 main board assembly the main board assembly contains the power supplies, a cpu/flash/ram bus, an fpga which provides audio switching and mode control, a class d switching audio a...
_________________________________________________________________ gma 347 maintenance manual page 3‐1 190‐00325‐02 rev. A section 3 troubleshooting this section contains basic tests which can be used to troubleshoot and confirm a defective unit. All tests are conducted with covers in place. There is...
_________________________________________________________________ page 3‐2 gma 347 maintenance manual view of j3471 connector from back of unit 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 ...
_________________________________________________________________ gma 347 maintenance manual page 3‐3 190‐00325‐02 rev. A table 3‐1. J3471 pin assignments (continued) pin pin name i/o 38 unswitched audio in 3 hi in 39 unswitched audio in lo in 40 reserved ‐‐ 41 reserved ‐‐ 42 tel audio in hi in 43 t...
_________________________________________________________________ page 3‐4 gma 347 maintenance manual view of j3472 connector from back of unit 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 ...
_________________________________________________________________ gma 347 maintenance manual page 3‐5 190‐00325‐02 rev. A table 3‐2. J3472 pin assignments (continued) pin pin name i/o 38 rs‐232 out 2 out 39 rs‐232 in 2 in 40 config module data i/o 41 speaker audio out lo out 42 speaker audio out hi ...
_________________________________________________________________ page 3‐6 gma 347 maintenance manual rev. A 190‐00325‐02 3.2 test procedures 3.2.1 power checks buss power this test will verify the audio panel can be powered by buss 1 and buss 2. Buss 1 and buss 2 are “ored” internally by diodes. Ai...
_________________________________________________________________ gma 347 maintenance manual page 3‐7 190‐00325‐02 rev. A led annunciators verify proper operation of the led annunciators. Marker beacon annunciations verify proper operation of the marker beacon annunciators. Volume and squelch contro...
_________________________________________________________________ page 3‐8 gma 347 maintenance manual rev. A 190‐00325‐02 4. Check pilot and copilot ics positions for isolation and proper operation of volume and squelch controls. 3.2.6 aircraft receivers check select the audio source corresponding t...
_________________________________________________________________ gma 347 maintenance manual page 4‐1 190‐00325‐02 rev. A section 4 repair repair is accomplished by removing and replacing a defective board/assembly and performing a return to service test. 4.1 tools standard avionics shop tools are u...
_________________________________________________________________ page 4‐2 gma 347 maintenance manual rev. A 190‐00325‐02 remove the front panel sub‐assembly: 1. Remove [by pulling forward] the volume and squelch knobs (11) from the front panel sub‐assembly (13). 2. Using a 7/16 nut driver or deep w...
_________________________________________________________________ figure 4‐1. Audio panel final assembly drawing gma 347 maintenance manual page 4‐3 190‐00325‐02 rev. A.
_________________________________________________________________ page 4‐4 gma 347 maintenance manual rev. A 190‐00325‐02 4.2.2 reassembly reassembly of the audio panel is the reverse of assembly. 4.3 service parts list the following table lists all of the parts that can be ordered from garmin to re...