AR 10046494, Operating And Service Manual, Page: 49 / 60

Model 60/40S1G18B
Rev A 29
4.3.6 Liquid Coolant
1. If there is a coolant temperature fault, check ambient temperature (too high or too low). If within spec,
check that the fans on the radiator and rear of the amp are operational.
2. If flow fault, check the coolant level, then check quick disconnect.
3. If both are fine, check to see if the pump has stopped.
4.3.7 PS1 Fault (Schematic 10046186)
The PS1 power supply has DC OK output which is normally low (< 0.1V) to the A14A3 J5/P12, pin 29. If
any of the PS1 outputs fail, this output will go high (> 4.0V) and inhibit the Low Band and High Band Pre-
Amplifier. PS1 is not repairable and will need to be replaced.
4.3.8 High Band PS2 Fault (Schematic 10046186)
The PS2 power supply has DC OK output which is normally low (< 0.1V) to the A14A3 J5/P12, pin 28. If
any of the PS2 outputs fail, this output will go high (> 4.0V) and inhibit the A1A1 PreAmp12V. PS2
is not repairable and will need to be replaced.
4.3.9 Low Band PS3 Fault (Schematic 10046186)
The PS3 power supply has DC OK output which is normally low (< 0.1V) to the A14A3 J5/P12, pin 23. If
any of the PS2 outputs fail, this output will go high (> 4.0V) and inhibit the A7 Pre-Amp15V. PS3 is
not repairable and will need to be replaced.
4.3.10 Low Band Amplifier Faults (Schematic 10046186)
1. The individual fault outputs for the Quadrature-Coupled Amplifiers (Quad Amps) A8, A10, A11, A12
and A13 are sensed on the A14A3 Switch Breakout Assy J5/P12 Pin12, Pin13, Pin14, Pin 15 and Pin 16
respectively.
2. The Amplifier Fault LED (DS1) should be lit, indicating the Quad Amp has failed.
3. Verify the correct voltages to the Quad Amp. Troubleshoot any incorrect voltages.
C1 = –5.0 ± 0.4V
C4 = +25.7 ± 0.2V