Service manual

62-11389
7−109
Alarm
NO.
Steps Alarm/Cause Corrective Action
249 MICROPROCESSOR ERROR
• TRIGGER–ON: Microprocessor Input Conversion Error.
• UNIT CONTROL: Shutdown and alarm.
• RESET CONDITION: Auto Reset when input conversions are valid, or Alarm may be manually
reset by turning the unit off, then back on again.
Follow the steps below until a problem is found. Once a repair or correction has been made, clear the alarm(s).
(See Note 1 page 7−2.) Operate the unit through the appropriate modes to see if any active alarm occurs.
Continue with the steps below as necessary.
1 Check Software Revision
Check microprocessor software revi-
sion.
Upgrade to the latest revision of software.
2 Check Microprocessor
a. Check Temperature Sensor Data Must be valid reading for RAT, SAT, AAT, etc.
b. Check for any Active Sensor
Alarms
Must all be cleared.
3 Check Microprocessor & Unit Wiring
Check Wiring to Micro and at input
devices to the micro.
Must not be miss-wired to allow 12 VDC on any of
the sensor input circuits.
4 Reset Microprocessor
a. Place the Main Power switch in the
OFF position for 30 seconds, then
back to the desired position.
Microprocessor powers up OK
b. Alarm 249 remains active. Download (if possible) and replace microprocessor.
Refer to Section 5.7.