Table 9: Operational Performance Problems - Nellcor OxiMax N-550 Service Manual

Troubleshooting
Operational Performance
48
Table 8: Display/Alarms Problems (Continued)
Symptom
An alarm condition
exists but no alarm
(audible or visual) is
indicated.
Table 9 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 Disassembly Guide on page 55.

Table 9: Operational Performance Problems

Symptom
The pulse amplitude
indicator seems to
indicate a pulse, but the
digital displays show
zeroes.
SpO or pulse values
2
change rapidly; Pulse
Amplitude indicator is
erratic.
Recommended Action
Replace the Front Panel PCB. Refer to Front Case
Disassembly on page 58.
Recommended Action
The sensor may be damaged; replace it.
Replace the Front Panel PCB. Refer to Front Case
Disassembly on page 58.
The sensor may be damp or may have been reused too
many times. Replace it.
• An electrosurgical unit (ESU) may be
interfering with performance:
• Move the N-550 and its cables and sensors as
far from the ESU as possible.
• Plug the N-550 power supply and the ESU
into different AC circuits.
• Move the ESU ground pad as close to the
surgical site as possible and as far away from
the sensor as possible.
• Verify the performance with the procedures
detailed in Performance Verification on
page 7.
• Replace the Front Panel PCB. Refer to Front
Case Disassembly on page 58.