AR 10036733, Operating And Service Manual

Page: 39 / 44

Model 30S1G6
4.3.5 PS1 Fault (Schematic Diagram No. 10034509)
The PS1 power supply has DC OK output which is normally low (< 0.1V) to the A8 J13, pin 29. If any of
the PS1 outputs fail, this output will go high (> 4.0V) and inhibit the A1 Pre-Amplifier.
4.3.6 Amplifier Faults (Schematic Diagram No. 10034509)
1. The individual fault outputs for the Quadrature-Coupled Amplifier (Quad Amp) (A2, A4 and A5) are
sensed on the A8 Control/Fault Board, J13, pins 9-11.
2. The amplifier’s top cover can be removed to allow access to the A2, A4 and A5 Quad Amps.
3. The Amplifier Fault LED (DS1) should be lit, indicating the Quad Amp has failed.
4. Verify the correct voltages to the Quad Amp. Troubleshoot any incorrect voltages.
C1 = +26.8 ± 0.5V
C4 = -5.0 ± 0.4V
4.3.7 Low or No Power Output (DC Tests) (Schematic Diagram No.
10034509)
All indicators on the Model 30S1G6 are normal, the front panel vacuum fluorescent display (VFD) reads
Power On , and the cooling fan (B1) is operating.
1. Check the position of the RF Gain control—is it set to maximum gain?
2. Check the RF input to the unit—is it the correct amplitude and frequency?
3. Check the RF output connection from the unit—is it correctly connected to the load?
Is the coaxial cable okay?
4. Check the following voltages on the Power Supply. If any of the voltages are out of tolerance, correct
them before further troubleshooting.
PS1 C Module +26.8 V
±
0.5 V
PS1 DB Module Channel 1 +24 V
±
0.5 V
PS1 DB Module Channel 2 -24 V
±
0.5 V
5. Check the voltage on the feed thru caps of the A2 and A3 Quad Amps. Troubleshoot any incorrect
voltage.
C1 +26.8 V
±
0.5 V
C2 -5 V
±
0.5 V
6. Check the voltage on the feed thru caps of the A1 Pre-Amp, with the RF gain control at maximum gain.
Troubleshoot any incorrect voltages.
Rev A 23