Nellcor N-395 Operator's Manual page 73

If operating on battery power, the battery may be
missing or discharged. If the battery is discharged,
notify service personnel to charge or replace the
battery.
2. One or more display elements or indicators do not light
during the power-on self-test.
Do nor use the N-395; contact qualified service
personnel or your local Mallinckrodt representative.
3. The monitor is operating on battery power, even though
it is connected to AC.
Ensure that the supply voltage selector switch is set
to the proper voltage.
Make sure that the power cord is properly
connected to the N-3 95.
Check to see if power is available to other
equipment on the same AC circuit.
4. The Pulse Search Indicator is lit for more than 10
seconds (before any measurements are taken).
Check the sensor directions for use to determine if
an appropriate sensor is being used and if it is
applied properly. Check sensor and sensor cable
connections. Test the sensor on someone else. Try
another sensor or sensor cable.
Perfusion may be too low for the N-395 to track the
pulse. Check the patient. Test the instrument on
someone else. Change the sensor site. Try another
type of sensor.
Excessive patient motion may be preventing the
N-395 from tracking the pulse. Keep the patient
still, if possible. Verify that the sensor is securely
applied, and replace it if necessary. Change the
sensor site. Use a type of sensor that tolerates more
patient movement; for example, an adhesive sensor.