AR 10037990, Operating And Service Manual, Page: 36 / 54

Model 250T6G18
16 Rev A
System Shutdown Screen - In the event of a system shutdown due to a latched fault (i. e., a fault such as body
overcurrent or power low line that requires a reset), the MENU screen is replaced by a screen indicating the nature
of the fault. Softkey S4 (labeled OK) is implemented as a reset key; pressing S4 brings back the MENU screens.
Line 3 of MENU 1, which normally displays the operational state of the TWTA, is used as a fault display line
until the fault is cleared. When the fault clears the system will automatically resume the standby state and high
voltage on will be enabled once again.
Factory Service Screens - A number of screens intended for factory service and calibration are behind passwords
and are not accessible to the user.
System Malfunction Screens - A number of screens are reserved to display error messages. These messages are not
normally seen and indicate a malfunction of the TWTA. System malfunction messages include the following:
Database corrupt
Communication failure
Cannot restore
CU line voltage too low to operate. System shutdown
In the event that one of these appears, shut off the TWTA and contact an authorized service representative before
proceeding.
CAUTION:
Attempts to operate the TWTA despite control unit problems may result
in loss of the static RAM database and calibration information.