AR 10046494, Operating And Service Manual, Page: 48 / 60

Model 60/40S1G18B
28 Rev A
4.3.3 Thermal Fault-Lo Band (Schematic 10046186)
During a Thermal Fault, the front panel VFD should read LB THERM.
1. Try to reset the unit; if the unit resets and operates normally, check to see that the cooling fans (B6 and
B7) are operating normally and that the air inlet on the bottom of the unit and the air outlets on the rear of
the unit are not blocked.
2. If the unit does not reset and the cooling fan is operating normally, check the voltage at the A14A3
Control/Fault Board, J5/P12, Pin 17 should be
≤
0.1V.
3. If the voltage on J5/P12, Pin 17 is high, check the connection through S6 and S7 to ground.
4.3.4 Thermal Fault High Band (Schematic 10046186)
During a Thermal Fault, the front panel VFD should read HB THERM.
1. Try to reset the unit; if the unit resets and operates normally, check to see that the cooling fans on the
radiator and rear of amp are operating normally and that the air inlets on the bottom of the unit and the air
outlet on the rear of the unit are not blocked.
2. If the unit does not reset and the cooling fans are operating normally, check the voltage at the A14A3
Control/Fault Board, J5/P12, Pin 25, 26 & 27; it should be
≤
0.1V.
3. If the voltage on A14A3 J5/P12, Pin 25, 26 & 27 is high, check the thermal daisy chain through A1S1, S2
and S3 to ground.
4.3.5 Interlock Fault (Schematic 10046186)
The Model 60/40S1G18B is equipped with an interlock connector, which is located on the rear panel. The
interlock circuit can be used to sense the openings of doors to screen rooms, test chambers, and so forth, and
to turn off RF energy when these doors are opened.
NOTE: The Model 60/40S1G18B is shipped with a mating connector, which has a jumper between Pins 1 and
8, installed in the rear panel interlock connector. The unit will not operate unless the interlock
circuit is closed.
1. In the event of an Interlock Fault, the front panel VFD should read INTERLOCK FAULT .
2. Check to see if it is safe to be power up the unit—are there personnel present in the screen room, or are
doors to the screen room open?
3. After checking for safety, try to clear the Interlock Fault from the front panel by using the RESET switch.
4. If the Interlock Fault will not clear, check for continuity in the External Interlock Circuit (Pin 1 to Pin 8 in
the connector, which mate with P14 in the rear panel).
5. Check the voltage on A14A3 J5/P12, pin 30; it should be < 0.1V.
6. If the voltage on A14A3 J5/P12, pin 30 is high, check the interlock line to ground.