Related Manuals for Garmin GPS 155
Summary of Contents for Garmin GPS 155
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Page 1: Maintenance And Repair
MAINTENANCE AND REPAIR GARMIN INTERNATIONAL 1200 E. 151 st Street OLATHE, KANSAS 66062 GPS 155 MANUAL PART NUMBER: 190-00065-05 REVISION E, MARCH 26, 1998... -
Page 2: Table Of Contents
GENERAL DESCRIPTION ........page 1 DETAILED DESCRIPTION . - Page 3 FIGURE 1 GPS 155 BLOCK DIAGRAM ....... .page FIGURE 2 CONTROL/DISPLAY UNIT BLOCK DIAGRAM .
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Page 4: General Description
GENERAL DESCRIPTION The GPS 155 is a full-featured aviation GPS navigation instrument that offers not only a fixed panel mounted installation in its rack, but also provides a take-home capability. The GPS 155 utilizes the patent- ed GARMIN Multitrac system for tracking up to eight satellites simultaneously. -
Page 5: Detailed Description
Sealed package containing rechargable cells, fuse and wiring harness. 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 below shows the interrela- tionships between major circuits and modules within the GPS 155. -
Page 6: Main Board Assembly
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/receivers and the power supply. -
Page 7: Power Supply Circuits
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 circuits, and the battery charger. -
Page 8: Rf/If Assembly
(010-10032-03) first. In the event these data are lost, they may then be restored from the user data card before the unit is returned to service. Refer to Appendix A of the GPS 155 Pilot’ s Guide for additional information on user data card operation. -
Page 9: Altitude Decoder Board
Interface Board. The Altitude Decoder Board also provides a discrete input for the GPS SEQ switch. When grounded, this line activates the GPS 155’ s HOLD mode. This input is sent to the Main Board data bus via the Interface Board. -
Page 10: Troubleshooting
• 20 MHz Oscilloscope 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 shows the recommended repair for each self-test failure message. MESSAGE... -
Page 11: Initial Troubleshooting Operations
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. -
Page 12: Troubleshooting Chart
TROUBLESHOOTING CHART PROBLEM Unit will not power on Unit will not power off Display has horizontal or vertical lines Display has missing or dark pixels Figure 6 Main Board Testpoints (Bottom View) RECOMMENDED ACTION 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) Replace Main Board (see Section 3.2.4) - Page 13 TROUBLESHOOTING CHART (cont.) Display brightness not adjustable Annunciators & Keycaps have no backlighting Keycap backlighting not uniform Annunciators do not function No external annunciator output(s) (message, arrival, approach) Keycaps do not function properly Dual concentric (rotary) knobs do not function properly Approach select switch not functioning properly OBS select switch (“course select”...
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Page 14: Disassembly Instructions
This process may take 20-30 minutes. CAU- TION: All user waypoints/settings will be lost if the unit is reset. 2 The GPS 155 will eventually perform an AutoLocate™ and lock onto satellites, however this can add an additional 10-15 min- utes to the normal lock-on time. -
Page 15: Board And Module Disassembly
3. Remove the power/dimmer control knob and shaft (430-00010-00) by loosening the M3 x 3mm set screw (211- 00025-00) on the coupling sleeve (125-00021-00). (NOTE: On some early versions of the GPS 155, the shaft extension is connected directly to the power/dimmer switch without an in-line coupler. The control knob is glued to this one piece extension and cannot be removed. -
Page 16: Main Board Sub-Assembly Removal
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. -
Page 17: Battery Pack 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, Interface and Main Boards is not required to remove the battery pack from the unit.) 3. -
Page 18: Rotary Switch Assembly Removal
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). -
Page 19: Service And Testing
13. Install the top and bottom covers by reversing the steps followed in Section 3.1. MEMORY BATTERY REPLACEMENT The GPS 155 utilizes a built-in lithium battery to maintain user waypoints/settings stored in RAM. This battery has an operational life of up to five years. Should the battery require replacement, as indi- cated by the “Memory battery low”... -
Page 20: Rom Replacement
(A user data card is available to save user waypoints/settings prior to replacing the ROM. Refer to page 5 of this manual for more information.) 1. Turn the GPS 155 is turned off. 2. Remove the bottom cover as described in Section 3.1. -
Page 21: Figure 9 Rom Removal
9. Install the bottom cover by reversing the steps followed in Section 3.1. 10. Connect an outside antenna to the GPS 155, turn the unit on and allow it to recollect almanac data as described above. This process is complete when the “Collecting data” message is no longer displayed on the Message Page. -
Page 22: Final Test
Hold the ENT key down while rotating the power/dimmer knob clockwise from the ‘off' position. b. Verify that the GPS 155 enters test mode. There are three test patterns displayed when first activating test mode. The first test pattern illuminates all thirty-five pixels in the first character column of each row and cycles through the remaining nineteen character columns. - Page 23 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 be displayed: @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ @ f @ @ @ @ @ @ g @ @ @ @ @ @ h e @ @ @ @ @ @...
- Page 24 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.
- Page 25 Rotate the inner function knob to turn the front panel annunciators ON. Verify that all six annunciators on the GPS 155 are lit. e. Rotate the power/ dimmer knob counterclockwise, but not past the detent (off) position, to ensure that the annunciators are dimmable.
- Page 26 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.
- Page 27 Press the CRSR key. d. Press the ENT key on the GPS 155 to calibrate the unit. There will be a brief delay while the unit performs the calibration. Verify that the input course is now 150º ± 0.2º.
- Page 28 Monitor the external NiCad battery voltage on the DMM. r. Push the UNIT POWER switch on the test panel to turn off external power to the GPS 155. Verify that the Battery Test Page indicates “REMOTE BATT OK”. (The Battery Test Page indicates “REMOTE BATT TMP OK”...
- Page 29 GA 56 with DC power. A 10 dB cable is available through GARMIN (P/N 320-00088-00). c. Turn on the GPS 155. Go to the Satellite Status Page (see Pilot’s Guide for instructions). d. Allow the unit to lock onto the satellites. If the unit has current almanac data, it will list the visible satellites on the row labeled ‘SAT’...
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Page 30: Figure 6 Figure
PIN # DESCRIPTION GPS SEQUENCE HOLD LOW ALTITUDE D4 ALTITUDE A1 ALTITUDE A2 ALTITUDE A4 ALTITUDE B1 ALTITUDE B2 ALTITUDE B4 ALTITUDE C1 ALTITUDE C2 ALTITUDE C4 ALTITUDE COMMON Figure 10 J2 Rear Connector Pinout Definition... -
Page 31: Figure 11 J101 Rear Connector Pinout Definition
PIN # DESCRIPTION GPS D-BAR LEFT + GPS TO + GPS FLAG + GPS FLAG - GPS D-BAR RIGHT + GPS FROM + GPS OBI CLOCK GPS OBI DATA GPS APPROACH ARM LOW GPS SUPER FLAG HIGH RS-422 IN HI GPS ARRIVAL ALARM LOW GPS APPROACH ACTV LOW GPS ROTOR C... -
Page 32: Illustrated Parts List
SECTION 5 ILLUSTRATED PARTS LIST LIST OF REPLACEABLE PARTS The table below lists the parts which are available to authorized maintenance shops. -
Page 33: Assembly Drawings
ASSEMBLY DRAWINGS The following assembly drawings are provided for part identification and to aid in assembly/disassem- bly of the GPS 155. Figure 12 211-50227-05 211-50227-05 211-50227-05 211-50227-05 GPS 155 Assembly Drawing (View 1) -
Page 34: Figure 13 Gps 155 Assembly Drawing (View 2)
211-63234-08 012-00091-00 211-63234-08 211-50227-05 211-50227-15 012-00091-00 Figure 13 GPS 155 Assembly Drawing (View 2) -
Page 35: Figure 14 Gps 155 Assembly Drawing (View 3)
Figure 14 GPS 155 Assembly Drawing (View 3) Figure 15 011-00127-00 012-00091-00 P701 J701 GPS 155 Connector Diagram...