AR 10037990, Руководство по эксплуатации и обслуживанию, Страница: 46 / 54

Model 250T6G18
26 Rev A
Disconnect power, RF and any other interface connectors. On the rear of the unit, remove any screws used to
connect brackets to amplifier (two on each bracket). On the front of the unit, remove the four screws (two
outside screws on each side) mounting the front panel to the cabinet. Carefully slide the amplifier out of the
front of the cabinet.
2. Remove the six screws that secure the lower cover and the six screws that secure the upper cover. Remove the
covers to gain access to the interior of the TWTA.
3. Vacuum dust and debris from inside the enclosure. Clean dust from the TWTA and its flying leads. Remove
any dirt from around the five high voltage connectors. While the cover is off, check for loose wires,
components or fasteners.
4. Reassemble in reverse order. Reconnect cables.
CAUTION:
Be especially careful with type SMA RF connectors, which are fragile and
easily damaged when incorrectly aligned during the assembly process.
4.4 TROUBLESHOOTING
Symptom Possible cause
TWT or power supply overtemperature Air inlet filter dirty
Collector heat sink dirty
Inadequate clearance behind TWTA
High air inlet temperature
Defective blower or power supply
No response when main power turned on
Panel open interlock switch open
Control module display does not come up; unit does not
beep when powered up
Shorted or defective control module power supply
Control module failure
Control module does not boot EPROM(s) missing.
Control module "datalink failure" error appears HPA interface failure.
Fiberoptic link failure
+15 VDC supply failure
Heater power supply does not come up Defective low voltage power supply module
Defective heater power supply module
No high voltage Open external interlock
Keylock switch on "INHIBIT" or "REMOTE"
Defective high voltage power supply.
Voltages normal, but no RF output, helix current low No RF input
No pulse gate input in pulse mode
Defective remote control board
Defective SSA
Gain turned down
Open inhibit
After review of the symptoms of the failure, the user may want to check for a loose connector or component
especially after rough handling of the unit. Look externally for physical damage and internally for unmated or
loose parts.
The service technician should become familiar with the internal mechanical construction to permit correct re-
assembly. Limited troubleshooting may be conducted, with caution, based on the failure symptom and an
understanding of the logic/schematic diagrams.