Raytheon ST60, Service Manual

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Part 1. ST60 Instruments – Chapter 1. Speed
A22001
2 ST60 Instruments Service Manual 83142-1
No fail codes are generated since stage 2 is an audio/visual check. The following can,
however, be used as a guide to isolate a problem:
Failure Mode Action
No illumination Check TR14, TR13, TR15 and associated components.
Check all LEDs.
Keypad Illumination failure Check TR14, TR13, R22 and R23.
(LCD illumination will also be degraded) Check LED1-6 for open circuit.
Keypad illumination OK Check TR14, TR15, RN3, R24.
but degraded LCD illumination Check LED 7 and 8 for open circuit.
No beep when key pressed Replace keyswitch.
LCD segment(s) missing completely Check LCD solder pins for poor/dry joints.
Check IC3 for unsoldered pins.
Faint LCD segments Check LCD pins for shorts.
Check IC3 for shorts.
Press Key 1 and Key 2 together momentarily to progress to self-test stage 4 (stage 3
not supported on this instrument).
Self-test stage 4
Note: A known good transducer must be connected for this test.
A. The unit should display ‘TEST 4’ for 1 second.
B. Transducer test is performed.
Spin the paddle wheel within 15 seconds of entering this test. If the interface is
working correctly, “PASS” will be shown. Otherwise “FAIL 10” is shown.
If the test fails, do the following:
Check Failure Mode Action
Voltage at 12V_SPD No voltage or low voltage (<11.0) Check TR17, TR20, R63 and R64.
with 12V battery supply.
L7 Open circuit Replace L7
D3 Open circuit Replace D3
Voltage at TEMP pin Outside acceptable range of Check L9 for open circuit
0.76 to 1.00V (18 - 25 degrees C) Check R14
AVREF Outside acceptable range of Check TR4.
2.5V +/- 0.25v Check R74, 17
Press Key 1 and Key 2 together momentarily to exit self-test.