Self-Test Stage 4 - Raytheon ST60 Service Manual

10 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
No illumination
Keypad Illumination failure
(LCD illumination will also be degraded)
Keypad illumination OK
but degraded LCD illumination
No beep when key pressed
LCD segment(s) missing completely
Faint LCD segments
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: For this test, a known good transducer must be connected and placed in water
where an echo can be detected. Alternatively, and echo simulator can be used.
A. The unit should display "TEST 4" for 1 second.
B. Transducer test is performed.
If the interface is working correctly, "PASS" will be shown within 15 seconds.
Otherwise "FAIL 8" is shown.
If the test fails, do the following:
Check
Pulses at pins 8 and 10 of IC4
Pulses at drain of TR5
Pulses at drain of TR6
Pulses at DEPTH+ and DEPTH-
Depth receiver output pulses
at pin 11 of IC5
Press Key 1 and Key 2 together momentarily to exit self-test.
Part 1. ST60 Instruments – Chapter 2. Depth
Action
Check TR14, TR13, TR15 and associated components.
Check all LEDs.
Check TR14, TR13, R22 and R23.
Check LED1-6 for open circuit.
Check TR14, TR15, RN3, R24.
Check LED 7 and 8 for open circuit.
Replace keyswitch.
Check LCD solder pins for poor/dry joints.
Check IC3 for unsoldered pins.
Check LCD pins for shorts.
Check IC3 for shorts.
Failure Mode Action
No pulses Check R68, 76, 77.
Check IC4 and IC5 and replace if suspect (trace
pulses from IC3).
No pulses Check L5 and R19 for open circuit.
Replace TR5.
Replace T1.
No pulses Check L5 and R19 for open circuit.
Replace TR6.
Replace T1.
No pulses Check C11 and C12 for open circuit.
Replace T1
No pulses Fault diagnosis of the depth receiver circuit
requires specialist knowledge and the units
should be returned to Raytheon Marine Ltd.