Table 5-5: Operational Performance Problems - Nellcor NPB-190 Service Manual

Table 5-4: Display/Alarms Problems (cont. from page 5-4)
Condition
5. Alarm does not sound.
Table 5-5 lists symptoms of problems relating to operational performance (no
error codes displayed) and recommended actions. If the action requires
replacement of a PCB or module, refer to Section 6, Disassembly Guide.

Table 5-5: Operational Performance Problems

Condition
1. The Pulse Amplitude
indicator seems to
indicate a pulse, but the
digital displays show
zeroes.
2. SpO2 or pulse rate values
change rapidly; Pulse
Amplitude indicator is
erratic.
Recommended Action
1. Check speaker connection to UIF PCB.
2. Replace the speaker as described in Section 6,
Disassembly Guide.
3. If the condition persists, replace the UIF PCB.
Recommended Action
1. The sensor may be damaged; replace it.
2. If the condition still persists, replace the UIF
PCB.
1. The sensor may be damp or may have been
reused too many times. Replace it.
2. An electrosurgical unit (ESU) may be
interfering with performance:
ñ Move the NPB-190 and its cables and
sensors as far from the ESU as possible.
ñ Plug the NPB-190 and the ESU into
different AC circuits.
ñ Move the ESU ground pad as close to the
surgical site as possible and as far away
from the sensor as possible.
3. Verify performance with the procedures
detailed in Section 3.
4. If the condition still persists, replace the UIF
PCB.
Section 5: Troubleshooting
5-5