Garmin GPS 155 Repair Manual

Also see for GPS 155: Pilot's guide addendum

Garmin GPS 155 Repair Manual Manual pdf 22 page image

4.3 FINAL TESTAfter completing all necessary maintenance or service, the following test procedure is provided toensure 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 and Black Cables with Banana Plugs (3’ length recommended)• Digital Multimeter4.3.2 Setup1. Preset the power supply to +28 VDC.2. Connect the positive output of the power supply to the red DC IN + jack at the back of the test panel. Connectthe negative output of the power supply to the black DC IN - jack at the back of the test panel.3. Connect the J2 and J101 wiring harness assemblies to the front of the test panel.4. Connect the positive and negative digital multimeter leads to the HI and LO FUNCTION SELECT outputson the front of the test panel. Set the DMM to measure DC voltage.5. Set the CAL/NORMAL switch to NORMAL and set the GPS 150/(155/155)/GNC switch to GPS155/155.6. Plug one end of the AC power cord into the back of the test panel and the other end into a 120VAC outlet.7. Turn the FUNCTION SELECT switch to POWER IN. Ensure that the PANEL POWER and UNIT POWER push-button switches are OFF (not lighted).8. Turn on the power supply, push the PANEL POWER switch and verify that it lights up. Push the UNIT POWERswitch and verify that it lights up.9. Monitor the POWER IN voltage with the DMM and set the power supply for +28.0 VDC.10. Push the UNIT POWER switch to turn unit power OFF.11. Connect the J2 and J101 wiring harness assemblies to the back of the GPS 155.12. Push the UNIT POWER switch to turn unit power ON.4.3.3 Final Test Procedure1. Test Mode Activation / Display Test:a. 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 activatingtest mode. The first test pattern illuminates all thirty-five pixels in the first character column of eachrow and cycles through the remaining nineteen character columns. The second test patternilluminates the first column of pixels in each of the 20 character columns and cycles through theremaining four pixel columns. The third test pattern illuminates the first row of pixels in each of thethree character rows and cycles through the remaining six pixel rows.19