Nellcor OxiMax N 5500 User manual

Service Manual
Patient Monitor

SERVICE MANUAL
For N5500 Patient Monitor
Tyco Healthcare
15 Hampshire Street Mansfield, MA02048, U.S.A.
Tyco Healthcare EMEA (Europe, Middle East and Africa)
Tyco Healthcare UK Ltd. 154 Fareham Road, Gosport PO13 OAS, U.K.
EU Representative
Tyco Healthcare UK Ltd. 154 Fareham Road, Gosport PO13 OAS, U.K.
Tel: [phone] Fax: [phone]
Manufactured for Tyco Healthcare Mansfield, MA 02048, U.S.A.
Manufactured by Mediana Co.,Ltd. 231-6 Nonhyun-Dong, Kangnam-Ku, Seoul, Korea
Copyright © 2003Tyco Healthcare. All rights reserved.

Notice
This document contains proprietary information which is protected by copyright. All Rights Reserved.
Reproduction, adaptation, or translation without prior written permission is prohibited, except as
allowed under the copyright laws.
Warranty
The information contained in this document is subject to change without notice.
Tyco Healthcare makes no warranty of any kind with regard to this material, including, but not limited
to, the implied warranties or merchantability and fitness for a particular purpose.
Tyco Healthcare shall not be liable for errors contained herein or for incidental or consequential
damages in connection with the furnishing, performance, or use of this material.
Revision/Printing History
The documentation printing date and part number indicate its current edition. The printing date changes
when a new edition is printed in accordance with the revision history of the documentation. Minor
corrections and updates which are incorporated at reprint do not cause the date to change. The
document part number changes when extensive technical changes are incorporated.

Contents
Figures
Tables
N5500 Service Manual i
Introduction & Maintenance
Introduction.................................................................................................................................... 1
1.1 Manual Overview ................................................................................................................ 3
1.2 Related Documents.............................................................................................................. 3
1.3 Description of the N5500 Patient Monitor ............................................................................. 3
Routine Maintenance ...................................................................................................................... 7
2.1 Cleaning.............................................................................................................................. 7
2.2 Periodic Safety and Functional Checks .................................................................................. 7
2.3 Functional Checks ............................................................................................................... 8
2.4 Batteries.............................................................................................................................. 8
2.5 Environmental Protection ..................................................................................................... 8
Performance Verification
Performance Verification................................................................................................................ 9
3.1 Introduction......................................................................................................................... 9
3.2 Equipment Needed............................................................................................................... 9
3.3 Performance Tests...............................................................................................................10
3.4 Safety Tests........................................................................................................................23
Default Settings & Troubleshooting
Service Menu and Factory Default Settings .................................................................................. 29
4.1 Introduction........................................................................................................................29
4.2 Service Menu .....................................................................................................................29
4.3 Demo Mode .......................................................................................................................34
4.4 Factory Default Settings ......................................................................................................34
Troubleshooting............................................................................................................................ 37
5.1 Introduction........................................................................................................................37
5.2 How to Use This Section .....................................................................................................37
5.3 Who Should Perform Repairs ..............................................................................................37
5.4 Replacement Level Supported .............................................................................................37
5.5 Troubleshooting Guide ........................................................................................................38
Disassembly Guide & Spare Parts
Disassembly Guide ........................................................................................................................ 45
6.1 General..............................................................................................................................45
6.2 Replacement Level Supported .............................................................................................47
6.3 Prior to Disassembly ...........................................................................................................47
6.4 Fuse Replacement...............................................................................................................47
6.5 Battery Disassembly ...........................................................................................................49
6.6 Monitor Disassembly ..........................................................................................................50
6.7 Front Case Disassembly Procedures.....................................................................................51
6.8 Rear Case Disassembly Procedures......................................................................................56
6.9 Optional Printer Assembly/Disassembly Procedures .............................................................65

Contents
ii N5500 Service Manual
Spare Parts ................................................................................................................................... 67
7.1 Introduction .......................................................................................................................67
7.2 Obtaining Replacement Parts...............................................................................................67
7.3 Parts List............................................................................................................................67
Packing For Shipment .................................................................................................................. 71
8.1 General Instructions ............................................................................................................71
8.2 Returning the N5500...........................................................................................................71
8.3 Repacking In Original Carton ..............................................................................................71
8.4 Repacking In a Different Carton ..........................................................................................72
Technical Information
Specifications ................................................................................................................................ 73
9.1 Display ..............................................................................................................................73
9.2 Controls .............................................................................................................................73
9.3 Alarms ...............................................................................................................................73
9.4 Physical.............................................................................................................................73
9.5 Electrical............................................................................................................................74
9.6 Environmental Conditions ...................................................................................................74
9.7 Measurement Parameters ....................................................................................................75
9.8 Trends................................................................................................................................77
9.9 Compliance........................................................................................................................78
System Processing Description...................................................................................................... 81
10.1 System Overview..............................................................................................................81
10.2 System Block Diagram......................................................................................................81
10.3 ECG Processing ................................................................................................................87
10.4 NIBP Processing ...............................................................................................................87
10.5 SpO2 Processing ...............................................................................................................89
10.6 Respiration Processing ......................................................................................................91
10.7 Temperature Processing.....................................................................................................92

Contents
N5500 Service Manual iii
Figures
Figure 1. N5500 Front Panel.............................................................................................................................................................4
Figure 2. N5500 Rear Panel..............................................................................................................................................................5
Figure 3. N5500 Right Side Panel .....................................................................................................................................................6
Figure 4. N5500 Left Side Panel........................................................................................................................................................6
Figure 5. The access ofService Menu via Set-up menu...................................................................................................................29
Figure 6. Service Menu....................................................................................................................................................................30
Figure 7. Disassembly Sequence Flow Chart..................................................................................................................................46
Figure 8. N5500 Exploded View ......................................................................................................................................................68
Figure 9. N5500 System Block Diagram 1.......................................................................................................................................81
Figure 10. N5500 System Block Diagram 2.....................................................................................................................................82
Figure 11. N5500 System Block Diagram 3.....................................................................................................................................82
Figure 12. Power Unit Block Diagram............................................................................................................................................83
Figure 13. Process Unit Block Diagram..........................................................................................................................................83
Figure 14. User-Control Unit Block Diagram.................................................................................................................................83
Figure 15. Sound Unit Block Diagram............................................................................................................................................84
Figure 16. Communication Unit Block Diagram.............................................................................................................................84
Figure 17. GUI Unit Block Diagram...............................................................................................................................................84
Figure 18. Thermal Printer Unit Block Diagram............................................................................................................................84
Figure 19. NIBP Unit Block Diagram.............................................................................................................................................85
Figure20. ECG Unit Block Diagram..............................................................................................................................................85
Figure 21. Respiration Unit Block Diagram....................................................................................................................................85
Figure 22. SpO2 Unit Block Diagram.............................................................................................................................................85
Figure 23. Temperature Unit Block Diagram..................................................................................................................................86
Figure 24. Analog Control Unit Block Diagram.............................................................................................................................86
Figure 25. Oxyhemoglobin Dissociation Curve...............................................................................................................................90
Tables
Table 1. Required Test Equipments ....................................................................................................................................................9
Table 2. Parameter Alarm Limit Factory Defaults ..........................................................................................................................14
Table 3. Earth Leakage Current Values ...........................................................................................................................................24
Table 4. Enclosure Leakage Current................................................................................................................................................24
Table 5. Patient Leakage Current Values.........................................................................................................................................25
Table 6. Patient Leakage Current Values - Mains Voltage on Applied Part....................................................................................26
Table 7. Test Lead Combinations.....................................................................................................................................................27
Table 8. Allowable Leakage Current................................................................................................................................................27
Table 9. Service menu......................................................................................................................................................................31
Table 10. NIBP Test Mode................................................................................................................................................................33
Table 11. System Information...........................................................................................................................................................33
Table 12.Factory Default Settings for the N5500 ...........................................................................................................................34
Table 13. Problem Categories..........................................................................................................................................................38
Table 14. Power Problems...............................................................................................................................................................39
Table 15. Display.............................................................................................................................................................................40
Table 16. Switches/Knob Problems..................................................................................................................................................41
Table 17. Alarms/Audible Tones Problems......................................................................................................................................41
Table 18. Operational Performance Problems ................................................................................................................................42
Table 19. Technical Error Codes......................................................................................................................................................43
Table 20. N5500 Parts List...............................................................................................................................................................69

Section 1: Introduction
1.1 Manual Overview
1.2 Related Documents
1.3 Description of the N5500 Patient Monitor
N5500 Service Manual 1
Introduction and
Maintenance, N5500
Warnings
Warnings are identified by the WARNING symbol shown above.
Warnings alert the user to potential serious outcomes (death, injury, or adverse
events) to the patient or user.
WARNING: Explosion hazard. Do not use the N5500 in the presence of
flammable anesthetics or gases.
WARNING: Do not spray, pour, or spill any liquid on the N5500, its accessories,
connectors, switches, or openings in the chassis.
WARNING: Do not immerse the N5500 or its accessories in liquid or clean with
caustic or abrasive cleaners.
WARNING: Ensure that conductive portions of the electrodes, leads, and cable do
not come into contact with any other conductive parts.
WARNING: Before attempting to open or disassemble the N5500, disconnect the
power cord from the N5500
WARNING: The LCD panel contains toxic chemicals. Do not ingest chemicals
from a broken LCD panel.
WARNING: The use of accessories, transducers, and cables other than those
specified may result in increased emission and/or decreased immunity of the
N5500 patient monitor.
WARNING: Do not silence the N5500 audible alarm or decrease its volume if
patient safety could be compromised.

Introduction
2N5500 Service Manual
Introduction and
Maintenance, N5500
WARNING: During the safety test, AC mains voltage will be present on the
applied part terminals. Exercise caution to avoid electrical shock hazard.
WARNING: Do not place the N5500 into operation after repair or maintenance
has been performed, until all Performance Tests and Safety Tests listed in section
3 of this service manual have been performed. Failure to perform all tests could
result in erroneous monitor readings.
WARNING: High voltage is generated by the LCD backlight driver. Exercise
caution when operating monitor with covers open..
Cautions
Cautions are identified by the Caution symbol shown above.
Cautions alert the user to exercise care necessary for the safe and effective useof
the N5500 monitor.
CAUTION: Observe ESD (electrostatic discharge) precautions when working
within the unit and/or when disassembling and reassembling the N5500 patient
monitor and when handling any of the components of the N5500 patient monitor.
CAUTION: When reassembling the N5500, over-tightening could strip out the
screw holes in the cases, rendering it unusable.
CAUTION: If any problem with N5500 built in an optional printer, check a
printer’s door is closed well. Operating error may be caused if the cover is not
closed correctly.
CAUTION: If internal battery cable has been disconnected, pay particular
attention to polarity of the cable before reattaching. If battery cable polarity is
reversed, it is likely that circuit damage will occur.
CAUTION: Ferrite Cores are used for electromagnetic compatibility. Please do
not remove Ferrite Cores while disassembling or reassembling, otherwise the
monitor can be affected by electromagnetic interference and measure inaccurate
data to be displayed or stored.
CAUTION: When reassembling, never forget that one of four screws on the back
bracket must be connected to green ground cable of the power inlet. This method
is for protecting dormant electrical shock hazards to operator or service engineer.

Introduction
N5500 Service Manual 3
Introduction and
Maintenance, N5500
1.1 Manual Overview
This manual contains information for servicing the N5500 patient monitor.
The monitor subsequently referred to as N5500 throughout this manual. Only qualified
service personnel should service this product. Before servicing the N5500, read the
operator’s manual carefully for a thorough understanding of safe operation.
Read and understand all safety warnings and service notes printed in this service
manual and the operator’s manual part number MDR05002-A7008.
1.2 Related Documents
To perform test and troubleshooting procedures and to understand the principles of
operation and circuit analysis sections of this manual, you must know how to operate
the monitor. Refer to the N5500 operator’s manualpart number MDR05002-A7008.
To understand the various Nellcor sensors, ECG leads, blood pressure cuffs, and
temperature probes that work with the monitor, refer to the individual directions for
use that accompany these accessories.
1.3 Description of the N5500 Patient Monitor
The purpose and function of the Nellcor N5500 patient monitor is to monitor ECG,
heart rate, noninvasive blood pressure (systolic, diastolic, and mean arterial pressures),
functional arterial oxygen saturation, respiration, and temperature for adult, pediatric
and neonate patients in all hospital areas and hospital- type facilities. It may be used
during hospital transport and in mobile, land-based environments, such as ambulances,
within the specification of the environmental characteristics. It is not intended for home
use. Monitor users should be skilled at the level of qualified health care professionals,
such as a technician, doctor, nurse or medical specialist.
Note: Hospital use typically covers such areas as general care floors, operating rooms,
special procedure areas, intensive and critical care areas, within the hospital plus
hospital-type facilities. Hospital-type facilities include physician office based
facilities, sleep labs, skilled nursing facilities, surgicenters, and sub-acutecenters.
Note: Intra-hospital transport includes transport of a patient within the hospital or
hospital-type facility.

Introduction
4N5500 Service Manual
Introduction and
Maintenance, N5500
The physical and operational characteristics of the monit or are described in the
operator’s manual and in the Specifications section of this manual.
Figure 1 and 2 identify the displays, controls, indicators and symbols of the front and
rear panels.
1. Waveform Display Icon 14. Home Switch
2. Graphic Frame15. Date and Time Display
3. Message Frame 16. Alarm Silence/Suspend Switch
4. Set-up Icon 17. Knob Switch
5. Alarm/Limits Icon 18. Low Battery Indicator
6. Big Numbers Icon 19. Battery Charging/ AC Power Indicator
7. NIBP Start/Stop Switch 20. Pulse Amplitude Indicator
8. Power On/Off Icon 21. Numeric Value Display
9. Power On/Off Button 22. SatSeconds Indicator
10. Power On/Off Indicator 23. Numeric Frame
11. Record Switch 24. Numeric Display Icon
12. Battery Icon 25. Alarm Indicator
13. Patient Mode Display
Figure 1. N5500 Front Panel
1
2
3
4
5
6 7 8910 11 12 13 14 15 16 17 18 19 20
120
140/100
(120)
mmHg
/min
T1
T2
24
%SpO 2
SpO2
1.0 cm
mV
/min
2122
180
120
100
140/100
(120)
RR
T1
T2
24
SpO 2
SpO 2
1mV
ECG
HR
37.0
180
ECG
Resp
NIBP
C
F
06/12/2002 08:12:23
Adult
23 24
25

Introduction
N5500 Service Manual 5
Introduction and
Maintenance, N5500
1. External DC Power Connector 7. Data Interface Symbol
2. Equipotential Terminal (Ground) 8. Data Port Connector
3. External DC Power Symbol 9. Network Connector
4. Fuse Holder 10. Network Symbol
5. Fuse Replacement (Fuse Label) 11. Product Label
6. AC Power Connector 12. Heat Sink
Figure 2. N5500 Rear Panel
The N5500 patient monitor has a color liquid crystal display (LCD). The Numeric
frames on the screen contain five numeric values are displayed. The Graphic Frames
contain three equally sized graphic frames in which real-time physiological waveforms,
graphical trend, or tabular trend data are displayed.
Controlling is accomplished by using the knob to interact with the appropriate area or
icon on the screen.
2 X
T 4.0A 250V
RS232
10~16V 5A
12
1 2 3 4 5 7 86 9
10
11

Introduction
6N5500 Service Manual
Introduction and
Maintenance, N5500
1ECG/Respiration Connector
2SpO2Connector
3NIBP Connector
4Temperature Connector (T2)
5Temperature Connector (T1)
Figure 3. N5500 Right Side Panel
1Optional thermal printer or Printer cover
Figure 4. N5500 Left Side Panel
1
1 2 3 4 5
T2
T1
SpO2
M4014-0

Section 2: Routine Maintenance
2.1 Cleaning
2.2 Periodic Safety and Functional Checks
2.3 Functional Checks
2.4 Batteries
2.5 Environmental Protection
N5500 Service Manual 7
Introduction and
Maintenance, N5500
WARNING: Do not spray or pour any liquid on the monitor or its accessories. Do
not immerse the N5500 or its accessories in liquid or clean with caustic or
abrasive cleaners.
2.1 Cleaning
To clean the N5500, dampen a cloth with a commercial, nonabrasive cleaner and wipe
the exterior surfaces lightly.
CAUTION: Do not allow any liquids to come in contact with the power connector
or switches or to penetrate connectors or openings in the instrument.
Note: For cables, sensors and cuffs, follow the cleaning instructions in the directions
for use that accompany these accessories.
Note: If liquid is spilled on the monitor, clean and dry thoroughly before reuse.
Note: If in doubt about monitor safety, refer the unit to qualified service personnel.
For surface-cleaning, follow your institution’s procedures or:
lThe N5500 may be surface-cleaned by using a soft cloth dampened with
either a commercial, nonabrasive cleaner or a solution of 70% alcohol in
water, and lightly wiping the top, bottom, and front surfaces of the monitor
lightly.
2.2 Periodic Safety and Functional Checks
The N5500 requires no routine service or calibration other than cleaning and battery
maintenance. The following performance verification tests may be used following
repair or during routine maintenance (if required by your localinstitution).
1. Inspect the exterior of the N5500 for damage.
2. Inspect labels for legibility. If the labels are not legible, contact Nellcor Technical
Services Department or your local Nellcor representative.
3. Verify that the unit performs properly as described in Performance Verification
section.

Routine Maintenance
8N5500 Service Manual
Introduction and
Maintenance, N5500
4. Perform the electrical safety tests detailed in Performance Verification section. If
the unit fails these electrical safety tests, do not attempt to repair. Contact Nellcor
Technical Services Department or your local Nellcor representative.
2.3 Functional Checks
The following checks should be performed at least every 2 years by a qualified service
technician.
1. If the monitor has been visibly damaged or subjected to mechanical shock (for
example, if dropped), perform the performance tests as described in Performance
Verification section.
2. Perform the electrical safety tests as described in Safety Tests section. If the unit
fails these electrical safety tests, refer to Troubleshooting section.
3. Inspect the fuses for proper value and rating (qty 2, 4.0 A, 250 volts).
2.4 Batteries
If the N5500 has not been used for a long period of time, the battery will need charging.
To charge the battery, connect the N5500 to an AC outlet as described in Paragraph
3.3.1 in this service manual or the Battery Operation section of the operator’s manual.
Nellcor recommends replacing the instrument’s battery every 2 years. When the N5500
is going to be stored for 2 months or more, it is recommended to remove the battery
prior to storage. To replace or remove the battery, refer to Disassembly Guide.
Note: Storing the N5500 for a long period without charging the battery may degrade the
battery capacity. The battery may require a full charge/discharge cycle to restore
normal capacity. Nellcor recommends that the N5500’s sealed, Ni-MH batteries
be replaced at 2-year intervals. Refer to Disassembly Guide Section.
Note:The battery cannot be charged by an external DC power source.
2.5 Environmental Protection
Follow local governing ordinances and recycling plans regarding disposal or recycling
batteries and other device components.

Section 3: Performance Verification
3.1 Introduction
3.2 Equipment Needed
3.3 Performance Tests
3.4 Safety Tests
N5500 Service Manual 9
Performance
Verification, N5500
3.1 Introduction
This section discusses the tests used to verify performance following repairs or during
routine maintenance. All tests can be performed without removing the N5500 covers.
All tests except the battery charge and battery performance tests must be performed as
the last operation before the monitor is returned to the user.
If the N5500 fails to perform as specified in any test, repairs must be made to correct
the problem before the monitor is returned to the user.
3.2 Equipment Needed
Table 1lists the equipment required for performance verification.
Table 1. Required Test Equipments
Equipment Description
Digital multimeter (DMM) Fluke Model 87 or equivalent
ECG cable for 3-leadwires MDEC No.2
ECG cable for 5-leadwires (optional) MDEC No.4
ECG leads MDEL series (MDEL-3S, MDEL-3G)
ECG leads (optional) MDEL series (MDEL-5S, MDEL-5G)
NIBP hose Colin Hose No.1EM/No.3EM
NIBP cuff Colin Cuff series
Pulse oximetry cable DOC-10
OXIMAX Durasensor® oxygen transducer DS-100A
OXIMAX oxygen transducer MAX-A
Temperature probes Monotherm™
SpO2simulator Nellcor SRC-MAX simulator
ECG simulator METRON PS-420 or equivalent
NIBP simulator Bio-Tek “BP Pump 2” or equivalent
Respiration simulator METRON PS-420 or equivalent
Temperature simulator medSim 300 or equivalent
Safety analyzer METRON QA-90 or equivalent
Data interface cable RS-232 cable
Stopwatch Manual or electronic

Performance Verification
10 N5500 Service Manual
Performance
Verification, N5500
3.3 Performance Tests
The battery charge and battery performance test should be performed before monitor
repairs whenever the battery is suspected as being a source of the problems. All other
tests may be used following repairs or during routine maintenance (if required by your
local institution). Before performing the battery performance test, ensure that the battery
is fully charged.This section is written using Nellcor factory-set power-up defaults. If
your institution has preconfigured custom defaults, those values will be displayed.
3.3.1 Battery Charge
1. Connect monitor to AC power source using proper power cord.
2. Verify AC Power indicator is lit.
3. Charge battery fully for at least 18 hours.
4. The only way to check for a full charge is to perform the procedure in paragraph
3.3.2 “Battery Performance Test.”
Note: The battery may require a complete charge/discharge cycle to restore its normal
capacity, depending on its previous usage.
3.3.2 Battery Performance Test
1. The N5500 monitor is specified to typically operate on battery power a minimum of
1hour, at 25°C, with no printing, and one NIBP measurement every 5 minutes.
Before performing this test, ensure that the battery is fully charged (paragraph 3.3.1).
2. Ensure monitor is not connected to AC power.
3. With N5500 turned off, press Power On/Off switch and verify battery icon appears at
bottom of display after power-on self-test is completed. Boxes in battery icon should
all be filled, indicating battery is charged.
4. Connect Nellcor SRC-MAX SpO2simulator to monitor via DOC-10 sensor cable.
5. Connect NIBP simulator to monitor via Colin-NO.EM hose.
6. Set SRC-MAX as follows: SpO2of 75% and pulse rate of 60 bpm.
7. Set NIBP simulator to simulate pressure setting of 120/80 mmHg and heart rate of 80
bpm.
8. Verify monitor is responding to SpO2simulator signal and audible alarm is sounding.
Use knob to select SpO2Menu and silence SpO2audible alarm (SpO2alarm suspend
condition).

Performance Verification
N5500 Service Manual 11
Performance
Verification, N5500
9. Use knob to select NIBP Menu and set Automatic Mode Interval to 5 minutes. Initial
NIBP measurement will be automatically taken in 5 minutes, then subsequent NIBP
measurements will be taken for 5 minutes, Automatic Mode Interval (from one
measurement completes to the next measurement starts).
10. N5500 monitor must operate for 1hour with a full-charged battery. N5500 monitor
must operate for at least 5 minutes before monitor automatically powers down due to
low battery condition.
11. Verify low battery alarm occurs and the low battery indicator is lit about 5minutes
before battery fully discharges.
12. Allow monitor to operate until it automatically powers down due to low battery
condition. Verify high priority alarm occurs 15 seconds before monitor automatically
shuts down.
13. If monitor passes this test, immediately recharge battery (3.3.1 Battery Charge).
3.3.3 Power-On Self-Test
1. Connect monitor to AC power source and verify AC Power indicator is lit.
2. Observe monitor front panel. With monitor off, press Power On/Off switch. Monitor
must perform the following sequence.
a. Monitor emits three consecutively higher pitched beeps.
b. Nellcor logo appears for a few seconds, with version numbers of the software
displayed in lower left corner of display.
c. Alarm Indicator (red) on the top of the front panel, AC power indicator
(green) and Low battery indicator (green) on the right bottom of the front
panel are illuminated.
d. Upon successful completion of power-on self-test, display will be in normal
monitoring screen configuration.
Note: Power-on self-test takes approximately 3seconds to complete.
Note: No vital signs numeric values or waveforms will be displayed.
3.3.4 General Operation Tests
3.3.4.1 Alarms and Alarm Silence
1. Press monitor Power On/Off switch to turn monitor on.
2. Connect SRC-MAX SpO2simulator to sensor input cable and connect cable to
monitor.
3. Set SRC-MAX as follows: SpO2of 75% and pulse rate of 60 bpm.

Performance Verification
12 N5500 Service Manual
Performance
Verification, N5500
4. Verify following monitor reaction:
a. Pulse bar begins to track artificial pulse signal from SRC-MAX.
b. After about 10 to 20 seconds, monitor displays saturation and pulse rate as
specified by simulator. Verify values are within following tolerances:
lTolerance of Oxygen Saturation : ±2 % SpO2
lTolerance of Pulse Rate : ±3 bpm
c. Audible alarm sounds and “Low SpO2limits violated”message will be
displayed and % SpO2numeric area will flash, indicating the parameter has
violated default alarm limits.
5. Press Alarm silence/suspend switch on monitor front panel. Audible alarm is
temporarily silenced.
6. Verify the following:
a. An audible alarm remains silenced.
b. Alarm silence icon appears in each numeric frame on display.
c. %SpO2display continuesflashing.
d. Audible alarm returns in approximately 60 seconds.
3.3.4.2 QRS Volume Control
1. Press monitor Power On/Off switch to turn monitor on.
2. Connect SRC-MAX SpO2simulator to sensor input cable and connect cable to
monitor.
3. Set SRC-MAX as follows: SpO2of 75% and pulse rate of 60 bpm.
4. Verify SpO2and pulse rate values are correctly displayed.
5. Press Alarm silence/suspend switch on front panel of the monitor to temporarily
silence audible alarm.
6. Verify heart rate tone source, found in ECG Menu, is set to “SpO2”.
7. Select Setup icon on the screen to display Set-up menu.
8. Rotate knob to highlight QRS volume on Set-up menu and press knob to adjust QRS
volume.
9. Set QRS volume 1 to 7 and return to the monitoring screen. Verify beeping pulse
rate tone increases.
10. Set QRS volume 7 to 1 and return to the monitoring screen. Verify beeping pulse
rate tone decreases.

Performance Verification
N5500 Service Manual 13
Performance
Verification, N5500
11. Set QRS volume to Off and return to the monitoring screen. Verify beeping pulse
rate tone is no longer audible.
12. Return QRS volume to a comfortable level.
3.3.4.3 LED Excitation Test
This procedure uses normal system components to test circuit operation. A Nellcor
OXIMAX oxygen transducer, model MAX-A, is used to examine LED intensity control.
The red LED is used to verify intensity modulation caused by the LED intensity control
circuit.
1. Connect the monitor to an AC power source.
2. Press the Power On/Off switch to turn the monitor on.
3. Connect DOC-10 pulse oximetry cable to the monitor.
4. Connect a MAX-A sensor to the pulse oximetry cable.
5. Leave the sensor open with the LEDs and photo detector visible.
6. After monitor completes its normal power-up sequence, verify that the sensor LED is
brightly lit.
7. Slowly move sensor LED in proximity of photodetector element of the sensor (close
the sensor slowly).Verify; as LED approaches the optical sensor, that the LED
intensity decreases.
8. Open the sensor and notice that the LED intensity increases.
9. Repeat step 7and intensity will again decrease. This variation is an indication that
the microprocessor is in proper control of LED intensity.
10. Press the Power On/Off switch to turn the N5500 monitor off.