Datex-Ohmeda Aestiva 7900 SmartVent Technical Reference Manual page 128

5 Troubleshooting
Message Alarm type/
Priority
Display Minimum
Voltage Out- Shutdown
of-Range
(6)
Exp Flow User Alarm
Sensor Fail
Exp Reverse medium
Flow (1)
(5)
5-12
Enabling Criteria Alarm Condition
Removal Criteria
Display voltage out-of-
range
The system cannot read Operation continues
the calibration data with default values.
stored in the sensor.
In-range flow data Negative flow on
available in mechanical expiratory sensor during
ventilation inspiration in circle
system
Two consecutive breaths measured with "correct"
flow seen by flow sensors
Service Repair
Check the VEL supply from service mode
under Display A/D channels. Verify that the
Counts value is between 1645 and 2675.
For machines with original CPU:
If not in range, measure the VEL supply on CPU
board at TP5 referenced to ground at TP1 (10
to 15.23 volts). If this voltage is in range,
replace the CPU board because the problem is
in the A/D channel.
If the VEL supply is not in range, remove
Display to CPU cable and re-test. If in range,
replace the display.
If not in range, measure VEL supply on Power
Supply board at TP22 referenced to ground at
TP16 (10 to 15.23 volts). If not in range then
remove power supply to CPU cable and re-test.
If still not in range, replace the power supply
board.
If voltage is in range on the power supply
board, replace the CPU board.
For machines with Integrated CPU:
If not in range, (Refer to section 5.6.3)
measure the VEL supply on CPU board at
TP213 referenced to ground at TP12 (10 to
15.23 volts). If this voltage is in range, replace
the CPU board because the problem is in the
A/D channel.
If the VEL supply is not in range, remove
Display to CPU cable and re-test. If in range,
replace the display.
If still not in range, replace the CPU.
Replace the flow sensor.
Check flow sensor connections for "No Flow
Sensor" alarm.
Check the breathing circuit
Perform flow sensor calibration.
Check insp/exp check valves.
Replace the flow sensors.
Check SIB to CPU cabling.
Replace the SIB board.
Replace the CPU board.
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