Nellcor OxiMax N-550, Service Manual

Page: 58 / 138

Troubleshooting
48
Operational Performance
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.
An alarm condition
exists but no alarm
(audible or visual) is
indicated. Replace the Front Panel PCB. Refer to Front Case
Disassembly on page 58.
Table 8: Display/Alarms Problems (Continued)
Symptom Recommended Action
Table 9: Operational Performance Problems
Symptom Recommended Action
The pulse amplitude
indicator seems to
indicate a pulse, but the
digital displays show
zeroes. The sensor may be damaged; replace it.
Replace the Front Panel PCB. Refer to Front Case
Disassembly on page 58.
SpO
2
or pulse values
change rapidly; Pulse
Amplitude indicator is
erratic.
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.