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- GPS 155
- Repair Manual
Garmin GPS 155 Repair Manual
Summary of GPS 155
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Gps 155 maintenance and repair manual garmin international part number: 190-00065-05 1200 e. 151st street revision e, march 26, 1998 olathe, kansas 66062.
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Table of contents section 1 introduction 1.1 general description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Page 1 1.2 detailed description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 1.2.1 control/display unit (cdu)...
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Section 5 illustrated parts list 5.1 list of replaceable parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Page 29 5.2 assembly drawings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 list of figures figure 1 gps 155 block diagr...
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Section 1 introduction this manual is intended to provide instructions and guidelines for the maintenance and repair of the garmin gps 155. Warning: this unit contains static sensitive devices. Service personnel must insure that proper precau- tions are taken to prevent damage to this equipment from...
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External battery pack: sealed package containing rechargable cells, fuse and wiring harness. 1.2 detailed description internally, the gps 155 is divided into six printed circuit boards: the main, rf/if, altitude decoder, interface, display, and keypad circuit boards. The block diagram in figure 1 be...
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The block diagram in figure 2 shows the interaction between components on the control/display unit. Figure 2 control/display unit block diagram 1.2.2 main board assembly the main board assembly contains the cpu, operating system rom, system memory, discrete i/o, ser- ial communication drivers/receiv...
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The block diagram in figure 3 below shows the interaction between the various main board circuits. Figure 3 main board block diagram 1.2.2.2 power supply circuits the power supply section of the main board supplies +60 volts for the display drivers, ±12 volts, +15 volts, +5 volts (vcc), on/off circu...
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The nicad battery charger circuit is built around the integrated circuit systems, inc. Ics1700a rapid charge controller. This controller uses a pulsed charging system, which is in effect when external power is supplied through the rear connector. When the unit is off, the batteries are not being cha...
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1.2.5 altitude decoder board the altitude decoder board contains the 26-pin rear connector (j2), discrete/parallel inputs and gillham/greycode decoder circuitry. Encoded pressure altitude data from a parallel altimeter device is received as a 10-bit data word at the 26-pin rear connector. Diode isol...
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Section 2 troubleshooting 2.1 troubleshooting equipment required • 0-30 volt dc / 3-amp power supply • digital multimeter • 20 mhz oscilloscope 2.2 self-test failures the gps 155 monitors many of its internal functions and displays a message to alert the user should a failure occur. The table below ...
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2.3 initial troubleshooting operations the first step in troubleshooting the gps 155 is to remove the top and bottom covers (see section 3.1). Verify that the unit is being properly powered and the internal clock is functional. Note: the navdata® card should be removed before disassembling the unit....
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Figure 6 main board testpoints (bottom view) 2.4 troubleshooting chart problem recommended action unit will not power on check external power connection check external battery pack(see section 3.2 & 4.3.2) replace pwr/dimmer switch (see section 3.2.7) replace main board (see section 3.2.4) unit will...
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Troubleshooting chart (cont.) display brightness not adjustable replace pwr/dimmer switch (see section 3.2.7) replace main board (see section 3.2.4) annunciators & keycaps have no backlighting replace control/display unit (see section 3.2.1) replace main board (see section 3.2.4) keycap backlighting...
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Troubleshooting chart (cont.) unit does not detect external check external power connection power4 replace main board (see section 3.2.4) no serial data output replace main board (see section 3.2.4) no external cdi output or external check connections and verify operation in test cdi functions impro...
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3.2 board and module disassembly 3.2.1 control/display unit (011-00127-00) removal 1. Remove the covers as described above. 2. Disconnect the battery pack wiring harness from the 3-pin locking connector (j800) on the main board (see figures 5 and 12). 3. Remove the power/dimmer control knob and shaf...
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3.2.4 main board sub-assembly removal the main board sub-assembly consists of the main board (012-00089-00) and the rf/if assembly (012-00091-00). If required, this sub-assembly may be further dismantled by following the steps in section 3.2.5. 1. Remove the covers as described in section 3.1. 2. Re...
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Figure 7 rf/if assembly removal 3.2.6 battery pack (011-00067-00) removal 1. Remove the covers as described in section 3.1. 2. Remove the heat sink clamping bar (115-00049-00, see figure 12-detail a) by removing the m3 x 5mm mounting screw (211-50227-05). (note: removal of the altitude decoder, inte...
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3.2.8 rotary switch assembly (011-cs033-00) removal 1. Remove the covers as described in section 3.1 2. Remove the control/display unit as described in section 3.2.1 3. Remove the two rotary switch knobs by loosening the two m3 x 4mm set screws on the inner knob (430-00002- 00). After removing the i...
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11. Install the control/display unit by reversing the steps followed in section 3.2.1. Gently slide the cdu onto the two main board connectors (j100 and j102), observing proper pin alignment during the process. 12. Connect the battery pack wiring harness to the 3-pin locking connector (j800) on the ...
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4.2 rom replacement if a software update is required, it may be performed by replacing the operating system rom located on the main board. When replacing the rom, all user waypoints/settings will be lost. The message “stored data lost” will be displayed. The unit must then be attached to an antenna,...
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D. Using a slight downward pressure, rotate the tool away from the chip carrier until the corner of the chip lifts away from the chip carrier socket. E. Repeat on opposite extraction slot and lift chip out of chip carrier socket. 5. Inspect the rom socket to ensure that the contacts and case are in ...
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4.3 final test after completing all necessary maintenance or service, the following test procedure is provided to ensure that all gps 155 functions are operating properly. 4.3.1 test equipment required • 0-30 volt dc / 3 amp power supply • gps 150/(155/155)/gnc manual test panel (t10-00003-02) • red...
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C. Observe the test patterns and verify that the display is working properly. D. Rotate the power/dimmer knob counterclockwise, but not past the detent (off) position, to ensure that the display is dimmable. 2. Cdi deflection test: a. Rotate the outer function knob clockwise. The cdi test page will ...
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5. Super flag output test: a. Rotate the outer function knob clockwise. B. Turn the function select switch on the test panel to position #4. C. If necessary, rotate the inner function knob to select in view. Verify that the dmm voltage is less than 0.25 vdc. D. Rotate the inner function knob clockwi...
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7. Rs-232 / rs-422 / arinc 429 loopback tests: a. Press the crsr key. B. Rotate the outer function knob until the i/o test page is displayed: c. Verify that the i/o test page indicates “ch 1 ok” and “ch 2 ok”. D. Verify that the i/o test page indicates “rs422 ok”. E. Verify that the i/o test page in...
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P. With the arrvl annunciator off, verify that the dmm voltage is greater than 4.5 vdc. Q. Rotate the inner function knob to turn the arrvl annunciator on. Verify that the dmm voltage is less than 0.3 vdc. 9. External switches test: a. Press the crsr key. B. Rotate the outer function knob until the ...
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11. Obs selected course test: a. Rotate the outer function knob until the obs selected course test page is displayed: b. Turn the obs bearing switch on the test panel to 150º. Verify that the input course is 150º ±9º and “calib?” appears in the lower right corner of the test page. C. Press the crsr ...
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M. Plug the wall charger jack into the charger socket at the rear of the gps 155. Verify that the battery test page indicates “trickle charge”. N. Unplug the wall charger jack from the gps 155. Verify that the battery test page indicates “rapid charge”. O. Allow sufficient time for the external nica...
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K. Press the set key. Verify that a set-up page (satellite status page) is displayed and the annunciator next to the set key is on. L. Press the rte key. Verify that a route page is displayed and the annunciator next to the rte key is on. M. Press the wpt key. Verify that the select waypoint type pa...
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Pin # description 13 gps sequence hold low 14 altitude d4 15 altitude a1 16 altitude a2 17 altitude a4 18 altitude b1 19 altitude b2 20 altitude b4 21 altitude c1 22 altitude c2 23 altitude c4 24 altitude common figure 10 j2 rear connector pinout definition 27 ? ? ? ? ? ? ? ? ? ? ? O@k? W&?@k? O@?@k...
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Pin # description 1 gps d-bar left + 2 gps to + 3 gps flag + 4 gps flag - 5 gps d-bar right + 6 gps from + 7 gps obi clock 8 gps obi data 9 gps approach arm low 10 gps super flag high 11 rs-422 in hi 12 gps arrival alarm low 13 gps approach actv low 14 gps rotor c 15 arinc 429 out b 16 arinc 429 out...
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Section 5 illustrated parts list 5.1 list of replaceable parts the table below lists the parts which are available to authorized maintenance shops. User data card 010-10032-03 rechargeable nicad battery pack 011-00067-00 control display unit 011-00127-00 tsoÕd rf/if assembly w/bnc connector 012-0009...
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5.2 assembly drawings the following assembly drawings are provided for part identification and to aid in assembly/disassem- bly of the gps 155. Figure 12 gps 155 assembly drawing (view 1) 30 211-50227-05 211-50227-05 211-50227-05 211-50227-05.
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Figure 13 gps 155 assembly drawing (view 2) 31 211-63234-08 211-63234-08 012-00091-00 012-00091-00 211-50227-15 211-50227-05.
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Figure 14 gps 155 assembly drawing (view 3) figure 15 gps 155 connector diagram 32 012-00091-00 p701 j701 011-00127-00