Garmin APOLLO GX SERIES, Service Manual

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Garmin AT Rev --
© 2004 Garmin AT GX Service Manual 7-7
Common Tests (All Units)
1. Display
Specification:
Verify that the display operates correctly.
Notes:
Use the Display Test function in the built-in test mode.
2. Display Brightness Control
Specification:
Verify that the display intensity dims when the photocell is covered, and returns
to bright when uncovered.
3. Front Panel Controls
Specification:
Verify all front panel buttons and rotary controls work properly.
Notes:
Use the Controls Test function in the built-in test mode.
4. Volume Control
Specification:
Verify the volume control can be adjusted from min to max or a count of 000 (full
counter clockwise) to 255 (full clockwise).
Notes:
Use the A-to-D Input test in the built-in test mode.
Although the GX50/55 does not use the volume control, it should still be checked.
5. Battery Voltage
Description:
A battery backs up The SRAM memory on the NAV board. The SRAM stores the
user waypoints and flight plans.
Setup:
Remove the cover from the unit (see Chassis Cover Replacement procedure).
Operation:
Measure the battery voltage using a DVM. Replace the chassis cover (see
Chassis Cover Replacement procedure) after verifying proper battery voltage.
Verification:
Verify that the battery voltage is in the range of 2.75 V to 3.4 V for an old battery
returning to service. A new battery should measure between 2.95 V and 3.4 V.