Technical Alarms Check Repair and Troubleshooting
5 - 8 046-001141-00 A5/A3™ Service Manual
5.2.4 Fresh Flow Sensor Board Alarm
Message
Priorit
y Cause Solution
Flowmeter Voltage Error High
DVCC, AVDD or VC
voltage error
1. Restart the machine.
2. Measure the 12V input voltage (voltage on the power cable) of
the electronic flowmeter to see if it is within specifications. Check if
the cable is defective. If the input voltage is out of specification,
replace the power board or cable.
3. If the problem persists, replace the fresh flow sensor board.
N2O Flow Too High Low
N2O flow is
greater than 15L/
min for 1 second.
1. Turn off other gas flow. Compare the concerned gas flow with the
measurement result displayed on the total flowmeter.
2. Use test tools. Turn Auto/Manual to Manual, Set APL valve at Max
value. Measure fresh gas flow at the inspiration connector. Check
the measurement error of electronic flowmeter.
3. If the problem persists, replace the flowmeter relative
subassembly.
O2 Flow Too High Low
O2 flow is greater
than 25L/min for 1
second.
Use the same method as “N2O Flow Too High” to “O2 Flow Too
High” to check the O2 flowmeter.
Air Flow Too High Low
Air flow is greater
than 20L/min for 1
second.
Use the same method as “N2O Flow Too High” to “Air Flow Too
High” to check the Air flowmeter.
O2-N2O Ratio Error High
N2O flow is
greater than 0.5 L/
min and greater
than 4 times O2
flow, this
condition last for
1.6 seconds.
1. Restart the machine.
2. Check the measurement correctness of O2 and N2O flow sensors.
If measurement error occurs, replace the flow sensor.
3. Check the ORC for leakage. Connect the tubes again. If an error
occurs, replace the ORC.
4. If the problem persists, replace the fresh flow sensor board.
Flowmeter Comm Stop High
Lost
communication
with CPU board
for 10 seconds.
1. Restart the machine.
2. Re-plug or replace the communication cable between the CPU
board and the fresh flow sensor board.
3. If the problem persists, replace the fresh flow sensor board.
5. If the problem persists, replace the CPU board.
NO Fresh Gas Med
Fresh gas flow is
less than 50 mL/
min
1.Check if the fresh gas knob is opened.
2. Check the measurement correctness of flow sensors. If
measurement error occurs, replace the flow sensor.
3. Check the ORC for leakage. Connect the tubes again. If an error
occurs, replace the ORC.
4. If the problem persists, replace the fresh flow sensor board.
Internal N2O Flow Failure Low
Communication
failure between
the electronic
flowmeter CPU
and N2O flow
sensor for 3s
continuously
1. Restart the machine.
2. Check the measurement correctness of flow sensors. If
measurement error occurs, replace the flow sensor.
3. If the problem persists, replace the fresh flow sensor board.