VPAP II LCD Group Service Manual Rev 5

Manufactured by: ResMed Ltd 1 Elizabeth MacArthur Drive Bella Vista NSW 2153 Australia Tel: +61 (2) 8884 1000 or 1 800 658 189 (toll free) Fax: +61 (2) 8883 3114 Email: [email protected] ResMed Offices: ResMed Corp 14040 Danielson Street Poway CA 92064-6857 USA Tel: +1 (858) 746-2400 or 1-800-424-0737 (toll free) Fax: +1 (858) 746-2900 Email: [email protected] ResMed (UK) Ltd 65 Milton Park Abingdon Oxfordshire OX14 4RX UK Tel: +44 (1235) 862 997 Fax: +44 (1235) 831 336 Email: [email protected] ResMed Asia Pacific Ltd 97 Waterloo Road North Ryde NSW 2113 Australia Tel: +61 (2) 9886 5000 or 1 800 991 900 (toll free) Fax: +61 (2) 9889 1471 Email: [email protected] ResMed Finland Niittykatu 6 FIN 02200 Espoo Suomi Tel: +358 9 8676820 Fax: +358 9 86768222 Email: [email protected] ResMed GmbH & Co. KG Rudolfstraße 10 D-41068 Mönchengladbach Deutschland Tel: +49 (0) 2161-3521-0 (Reception), +49 (0) 180 22 22 668 (Service-Telefon; 0.06 s/Anruf), +49 (0) 180 22 66 888 (Wartungstelefon; 0.06 s/Anruf) Fax: +49 (0) 2161-3521-1499 Email: [email protected] ResMed Hong Kong Ltd Room 1714 Miramar Tower 132-134 Nathan Road Tsim Sha Tsui Hong Kong Tel: +852 2366 0707 Fax: +852 2366 4546 Email: [email protected] ResMed Japan Nihonbashi Hisamatsu Bldg. 4F 2-28-1 Nihonbashi-Hamacho Chuo-Ku, Tokyo 103-0007 Japan Tel: +81 (3) 3662 5056 Fax: +81 (3) 3662 5040 ResMed Malaysia Sdn Bhd Suite E-10-20, Plaza Mon’t Kiara No. 2, Jalan 1/70C Mon’t Kiara 50480 Kuala Lumpur Malaysia Tel: +60 3 6201 7177 Fax: +60 3 6201 2177 Email: [email protected] ResMed NZ Ltd PO Box 51-048 Pakuranga Auckland New Zealand Tel: +0800 737 633 (NZ toll free) or +64 25 737 633 Fax: +0800 737 634 (NZ toll free) or +64 9 239 0193 Email: [email protected] ResMed SA Parc de la Bandonnière 2 rue Maurice Audibert 69800 Saint-Priest France Tel: +33 (0) 4 37 251 251 Fax: +33 (0) 4 37 251 260 Email: [email protected] ResMed Singapore Pte Ltd 238A Thomson Road # 12-03/04 Novena Square Tower A Singapore 307684 Tel: +65 6284 7177 Fax: +65 6284 7787 Email: [email protected] ResMed Spain SL C/ Arturo Soria, 245 28033 Madrid España Tel: +34 (93) 590 8154 Fax: +34 (93) 590 8153 Email: [email protected] ResMed Sweden AB Industrigatan 2 S-461 37 Trollhättan Sverige Tel: +46 520 420 110 Fax: +46 520 397 15 Email: [email protected] Labhardt AG Thannerstrasse 57 CH-4054 Basel Schweiz Tel: +41 (061) 307 9711 Fax: +41 (061) 307 9722 Email: [email protected] US DESIGNATED AGENT: ResMed Corp EU AUTHORISED REPRESENTATIVE: ResMed (UK) Ltd

Internet: www.resmed.com Protected by patents: AU 697652, AU 699726, AU 713679, EP(DE,FR,GB) 0661071, EP 0858352, US 4944310, US 5199424, US 5522382, US 6213119, US 6240921, US 6705315. Other patents pending. Sullivan, IPAP MAX, IPAP MIN, VPAP, VPAP MAX, and are trademarks of ResMed Ltd and Sullivan, IPAP MAX, VPAP and VPAP MAX and Vsync logo are Registered in U.S. Patent and Trademark Office. © 2005 ResMed Ltd 21881/5 05 03

Contents 1

How to use this manual... manual... 4

2

Introduction ... 5 Intended users of this manual Features of the VPAP II LCD group flow generators VPAP II Family enhancements Enhancements specific to the VPAP II ST-A Model types

3

5 5 6 7 7

General inspection and servicing ... 8 Instructions for general inspection procedures

10

4

Static Precautions ... 16

5

Replacing major subassemblies ... 17 Replacing PCBs Replacing the blower

6

Replacement parts ... 27 Outside cases Air path Blower and housing assembly (including motor, thermal switch & tubing) Printed circuit boards

7

28 31

34 36 36 38 38

Troubleshooting guide ... 39 Autotriggering

9

27 28

Final test and calibration procedures ... 34 Warnings and cautions VPAP II VPAP II ST & VPAP II ST-A Equipment set up and calibration Recommended order of test and calibration procedures

8

18 23

40

System specifications ... 41 SULLIVAN VPAP II and VPAP II ST with LCD SULLIVAN VPAP II ST-A with LCD

41 42

10 Recommended maintenance schedule ... 43 Appendix A: Service request form ... 44 Appendix B: VPAP II group schematic diagrams ... 45 Contents

3

1

How to use this manual Each of the sections in this manual have been written with a specific purpose in mind. Use this guide to help you find the material which is relevant to your task. 2 Introduction – Gives a brief overview of the VPAP II LCD group flow generators, and the different types. 3 General inspection and servicing – Gives the procedures to help you examine a flow generator which has been brought into a service centre. The procedure should be performed before any other work is done on the flow generator. The Record of Service at the beginning of this section acts as a checklist and a record of the service conducted on the flow generator. 4 Static precautions – Gives procedures to be followed whenever PCBs are removed from a VPAP II LCD group flow generator. These procedures will minimize the chance of ICs being damaged by static electricity. 5 Replacing major subassemblies – Points to note when replacing subassemblies, reassembling the flow generator, and indications of when recalibration is necessary. 6 Replacement parts – Gives labelled pictures and part numbers of all the spare parts and subassemblies available from ResMed Ltd. 7 Final test and calibration procedures – After a fault has been isolated on a particular PCB, and the PCB has been replaced, follow this procedure to test the unit thoroughly, to calibrate it, and to restore the owner's individual settings. A Final test and calibration record sheet has been included to record patient settings, calibration readings and results. Note:

It is essential that the owner's prescribed pressure be set using the same type of mask system and air tubing used by the owner.

8 Troubleshooting guide – If you know the symptoms of a faulty machine, use this guide to quickly locate the problem and repair it. 9 System specifications – Lists electrical and mechanical specifications of flow generators and air tubing. 10 Recommended maintenance schedule – A brief description of the maintenance which the owner of the flow generator should carry out. If the owner is performing regular cleaning and maintenance, there is no need for regular servicing by a service technician. Appendix A - Product Problem Report - Whenever you locate a fault in a VPAP II LCD, fill out this form and send it to ResMed for logging. Appendix B - Schematic diagrams - Circuit diagrams are provided for the PCBs used in the system. If you require larger copies, please contact ResMed with the names and numbers of the circuit diagrams you need. Note:

4

The circuit diagram number is different to the PCB number which is printed on the circuit board.

VPAP™ II LCD Group Service Manual

2

Introduction This manual is a guide to servicing and repairing SULLIVAN VPAP II (LCD), VPAP II ST (LCD), and VPAP II ST-A (LCD) flow generators. The service manual is written for ResMed distributors, and gives instructions for replacing subassemblies and for recalibration as appropriate. Work at the component level will normally be carried out by ResMed.

Intended users of this manual Before attempting any repair work, please ensure that you: • are familiar with the operating manuals and the clinical manuals for the flow generators in the VPAP II LCD group • have suitable electrical and mechanical training to satisfy the requirements of the relevant regulatory authorities • use the correct antistatic procedures described in this manual Use only approved ResMed parts and never use parts that have failed, show excessive wear, have been contaminated or are ineffective for their intended use.

Nasal VPAP SULLIVAN Nasal Positive Airway Pressure systems are used to treat obstructive sleep apnea, a disorder that causes physical obstruction in a person’s airway while sleeping. The principle of treatment is that filtered air is delivered by a flow generator through flexible tubing to a nasal mask worn by the patient while sleeping. The flow generator maintains a positive pressure in the patient’s airway which acts as a pneumatic splint, prevent the airway from collapsing during sleep. This positive air pressure is switched between a higher pressure (IPAP) while the patient breathes in and a lower pressure (EPAP) while the patient breathes out.

Features of the VPAP II LCD group flow generators The IPAP and EPAP pressures are adjustable and will be prescribed by a physician. The rate at which the pressures build up when the flow generator is started is also adjustable. The air pressure can be set to build up gradually, allowing a patient to fall asleep before the prescribed pressure is reached. Buttons on the front control panel set the pressure to build up quickly or over a period of 5, 10 or 20 minutes. It is also possible to vary the minimum and maximum IPAP times and control the switching between IPAP and EPAP pressures.

Internal pressure and flow sensors The VPAP II LCD group of flow generators have pressure and flow sensors which provide measurements of air pressure and flow rate, to ensure that prescribed pressure is maintained in spite of mask leak or high altitude. The sensors also make the SmartStart®/SmartStop feature possible. Note:

The VPAP II and VPAP II ST models have one pressure sensor, whereas the VPAP II ST-A model has two. The high and low pressure alarms use input from the second pressure sensor.

2 Introduction

5

The VPAP II ST-A is shipped to the US, Canada and South America with the low pressure, high pressure and power failure alarms enabled. Refer to the operating and clinical manuals for details of the different modes of operation available.

VPAP II Family enhancements Improved pressure rise time The Enhanced model has a faster rise time at the MIN setting, giving a rise time of approximately 90 ms at pressures of 5:15 (EPAP:IPAP).

Rise time comfort scale The rise time is now a stepped scale with additional settings of 150, 200, and 250. The scale is now {MIN, 150, 200,..., 900} in increments of 50 for faster adjustment.

Mask alarm All members of the VPAP family are now equipped with an optional mask alarm function. If high flow is detected, an audible and visual alarm will activate to indicate that the mask may have been dislodged. The alarm can be cancelled by pressing the Alarm Cancel button or by refitting the mask.

Breath per minute (BPM) increments BPM will now increase in integer increments of 1 BPM and therefore be selectable in whole breaths.

Improved patient hours accuracy Patient compliance hours now only records those hours when the patient is receiving the prescribed pressure, i.e., mask at pressure.

Standard flow outlet The VPAP Family now comes equipped with a standard ISO 22 mm tapered connector to enable secure fitting with ISO standard hospital accessories.

Automatic backlight The VPAP Family now has automatic backlight for the LCD. When in clinical mode the backlight will automatically illuminate when you press any of the menu and option buttons and will turn off when you have completed your changes. In patient mode, the backlight is permanently off, unless the Mask Alarm button is pressed to access patient hours, in which case the backlight will automatically illuminate for 30 seconds, displaying patient hours on the LCD.

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VPAP™ II LCD Group Service Manual

Enhancements specific to the VPAP II ST-A Expanded pressure range The VPAP II ST-A EPAP minimum settings has been lowered from 4 to 2 cm H2O giving a range of 2 to 25 cm H2O.

New silicone keys A silicone keypad has been fitted to the VPAP II ST-A, so now all VPAP models have the more robust keypad.

Model types Due to the number of variations in manufacture of VPAP II, the different models are referred to using type numbers, such as Type 4 or Type 5. The VPAP II Type 4 was the first model to use an LCD screen. The following table is a guide to identifying types and their characteristics: Type

Model

Software Versions Used

Characteristics

4

VPAP II

S064-0100, S064-0101, S064-0102, S064-0103

VPAP II ST

S064-0100, S064-0101, S064-0102, S064-0103

Through hole PCBs Rotron/Ametek motor

VPAP II ST-A

S064-0100, S064-0101, S064-0102, S064-0103

VPAP II

S064-0103

VPAP II ST

S064-0103

VPAP II ST-A

S064-0103

VPAP II

S064-0107, S098-0107

VPAP II ST

S064-0107, S098-0107

VPAP II

S064-0202, S064-0210, S064-0212

VPAP II ST

S064-0202, S064-0210, S064-0212

VPAP II ST-A

S064-0202, S064-0210, S064-0212

VPAP II

S064-0213

VPAP II ST

S064-0213

VPAP II ST-A

S064-0213

5

6

7

8

SMT PCBs Rotron/Ametek motor

Silicone keypad SMI motor Silicone keypad SMI motor

Higher breath detection threshold SMI motor

Most VPAP II Type numbers can be determined by looking up the software number in the above table. Note:

S064-0103 is used in both Type 4 and Type 5. In this case you also need to open the VPAP to check whether the PCB technology is through-hole (Type 4) or surface mount (Type 5).

2 Introduction

7

3

General inspection and servicing Make sure that the user’s mask and air tubing are received with the flow generator. If operational, set up the VPAP system and attach a closed Bubble Cushion® to the mask frame. Start the flow generator and leave it in standby mode for at least 15 minutes to allow it to warm up. This is to allow the pressure and flow transducers to stabilize. Check and record the set pressures of the system in the table on the following page as confirmation of the pressures stated by the user. Carry out the procedures on the following pages to confirm that the VPAP unit is in good electrical and mechanical condition. These tests will highlight any major mechanical or electrical problems. Enter the results of the tests in the table on the following page and retain this sheet as a record of service. If the flow generator fails any of these tests, refer to the troubleshooting guide and replace and faulty components. If any PCB or any parts of the air pathway are replaced, you must carry out the test and calibration procedure in Section 7 Final test and calibration procedures.

Equipment required • ResMed VPAP II Calibration Service Software version 2.1 (21951 - software only) or available in software kit 21908, which includes licence key, Smart cable, standard mask frame and closed bubble cushion. • Service Resuscitator kit 19278 which includes resuscitator, sideport oxygen connector, 22 mm straight adaptor and vent fitting flow orifice. • Calibrated flow meter with flow regulation valve Note:

The flow meter must be capable of measuring air flows ranging from 0 l/min to 140 l/min, with an accuracy of 3% over this range.

• 2 metre air hose • Manometer (0-30 cm H2O range) • A computer running Windows 98, NT 4.0, 2000, ME or XP.

Notation SW1 refers to the Stop/Start button, LED1 is the LED above the Stop/Start button. SW2 refers to the 5-minute button, LED2 is the LED above the 5-minute button. SW3 refers to the 10-minute button, LED3 is the LED above the 10-minute button. SW4 refers to the 20-minute button, LED4 is the LED above the 20-minute button. SW5 refers to the Mute button, LED5 is the LED above the Mute button.

8

VPAP™ II LCD Group Service Manual

Record of service 1

Clean flow generator

2

Record clinical settings

Completed

Pressure Clinical options

IPAP

Breath rate

EPAP

MAX IPAP time

Start

MIN IPAP time

Optional features

Rise time

SmartStart

If unit overheats, switch to

Humidifier

Operating mode

Mask-off Alarm

On

Off

On

Off

On

Off

3

External examination

Pass

Fail

Repaired/Pass

4

Internal examination

Pass

Fail

Repaired/Pass

5

Replace air filter

Completed

6

Self test

Pass

Fail

Repaired/Pass

7

MIN/MAX IPAP test

Minimum IPAP

Pass

Fail

Repaired/Pass

Maximum IPAP

Pass

Fail

Repaired/Pass

8

Flow test

Pass

Fail

Repaired/Pass

9

Operation test

Pass

Fail

Repaired/Pass

10

Alarm test

Pass

Fail

Repaired/Pass

11

Reload clinical settings

Completed

12

Fill in service request form

Completed

N/A

N/A

Service details Name of service agent

Date of service

Signature of service agent

Serial number

Reference number

Copyright 2005. ResMed Limited. Permission to reproduce in full solely for the purposes of servicing ResMed product.

3 General inspection and servicing

21881/5

9

Instructions for general inspection procedures Carry out the following procedures in the order given, and record the details on the Record of Service sheet on the previous page. 1

Clean flow generator Before servicing the unit it should be wiped down using a lint free cloth and a cleaning agent with a high alcohol content, e.g. isopropyl alcohol.

Caution

When using a cleaning agent with a high alcohol content refer to the appropriate Material Safety Data Sheet to ensure safe handling of the cleaning agent.

!

Remove any stains from the cases. When removing any stains from the flow generator or mask system use soap or detergent-based cleaning solutions. Remove excess and wipe dry after use. Do not use thinners, trichlorethylene, bleach or other solvents. Do not apply oil to any component of the flow generator. 2

Record clinical menu settings Make sure the user’s mask and air tubing are received with the flow generator. 1 Open the VPAP II Calibration software. 2 Select Settings>Set Operating Mode, Pressure and Options from the main window. 3 The following screen will appear with the clinical settings:

4 Select File>Save Screen Options to File, and save the settings under the unit’s serial number. 5 Record the setting for each parameter in the table provided in the record of service sheet. Note:

10

If the patient settings cannot be read prior to servicing, reload the default settings once servicing is complete. Notify the patient and inform them that the unit has been reset to default settings.

VPAP™ II LCD Group Service Manual

3

External examination Visually examine the flow generator for external damage such as: • deformation or cracking of the outside case • damaged components such as the mains power inlet or mains power switch • damage to the LCD window, information labels or front panel decal If no damage is detected go to procedure 5 “Replace the air filter”. If any damage is detected, you will need to open the flow generator and take particular care in inspecting all other components within the case for damage.

4

Warning

!

Internal examination (if necessary): The VPAP II flow generators use a non-isolated power supply. The power supply does not provide any primary/secondary isolation, so ALL circuitry in these flow generators is LIVE at mains potential! Whenever it is necessary to work with the cases opened up and power switched on, you must first connect an isolation transformer between the flow generator and the mains power supply. To open the flow generator, turn it upside down and remove the seven socket head screws which hold the top case and the bottom case together. Turn the flow generator right-side up again and remove the top case. Inspect the flow generator for the following, recording any irregularities: • all mechanical components are mounted correctly and secured in position • all electrical components are mounted correctly and secured in position • all silicone tubing is free from kinks • there are no loose terminals, loose wires or incomplete insulation on electrical components or connections • there are no loose pieces of wire or other objects trapped in PCBs or other areas of the bottom case • any evidence of decay or contamination of the acoustic foam in either the inlet baffle or the cases Rectify any problems noted during internal and external inspection of the flow generator. If any internal component needs to be replaced, refer to Section 5 Replacing major subassemblies for instructions. Refer to Section 8 Troubleshooting guide for help in determining which parts to replace.

Caution

!

Whenever any PCB or any part of the air pathway is replaced, the flow generator must be recalibrated by following the procedures in Section 7 Final test and calibration procedures Printed circuit boards can be damaged by static electricity. Please read the instructions in Section 4 Static Precautions before attempting to replace any PCBs. Thread cutting screws are used to fasten the PCBs to the case of the flow generator. When replacing a thread cutting screw, turn the screw anticlockwise until it fits into the previously cut thread. Otherwise the original thread may be stripped. Use a soft dry cloth to remove dust or dirt from components and from the insides of the flow generator case. Reassemble the flow generator. 3 General inspection and servicing

11

5

Replace the air filter • Remove the air filter cover from the flow generator. • Remove the old filter strips and replace with new ones.

Caution

Only use genuine ResMed spare parts, because the filter affects the flow characteristics of the flow generator, which in turn affects the pressure supplied to the patient.

!

Note: 6

More detailed instructions are supplied with the replacement filter strips.

Self test 1 Select Performance Tests>Self Test. 2 Follow the instructions on screen. 3 Record the results in the record of service form on page 9. 4 Once the self test is complete press the OK button. If the unit fails this test, follow the procedures outlined in Section 7 Final test and calibration procedures to do a full test and recalibration of the flow generator, or return the unit to ResMed for servicing.

7

Minimum/Maximum IPAP test 1 Select Performance Tests>Min/Max IPAP Test. 2 Follow the instructions on screen. 3 Record the results in the record of service form on page 9. If the unit fails this test, follow the procedures outlined in Section 7 Final test and calibration procedures to do a full test and recalibration of the flow generator, or return the unit to ResMed for servicing.

8

Flow test 1 Select Performance Tests>Flow Calibration Test. 2 Follow the instructions on screen. 3 Record the results in the record of service form on page 9. If the unit fails the flow test, follow the procedures outlined in Section 7 Final test and calibration procedures to do a full test and recalibration of the flow generator, or return the unit to ResMed for servicing.

12

VPAP™ II LCD Group Service Manual

9

Operational test (SmartStart/Stop and triggering) Note:

This test continues on from the minimum pressure test.

Set CPAP pressure, set spontaneous mode, turn on SmartStart/Stop 1 Select Settings>Set Operating Mode, Pressure and Options. 2 Set the IPAP pressure to 10 cm H2O. 3 Press SW3 to move the arrow on the LCD to IPAP. Change the IPAP pressure to 10 cm H2O. 4 Change the operating mode to SPON. 5 Select the SmartStart option. 6 Press the Set button to load the settings to the flow generator.

SmartStart/Stop test and triggering test 1 Remove the air tubing from the flow generator and insert a sideport oxygen connector onto the outlet port. Reconnect the air tubing to the sideport oxygen connector. 2 Remove the mask frame with closed bubble cushion from the air tubing and replace it with the resuscitator. 3 Connect the manometer to the sideport oxygen connector, as shown below:

Test set-up

Resuscitator

Manometer connected to sideport oxygen connector (Z305)

3 General inspection and servicing

13

Resuscitator set-up Resuscitator

22 mm straight adaptor Z9005 Vent fitting flow orifice R160-718

4 Start squeezing the resuscitator to simulate a person breathing, and confirm that the flow generator starts automatically. 5 Confirm that the flow generator switches between the IPAP and EPAP pressures. • When the unit reaches EPAP, squeeze the resuscitator. Check that the unit rises to IPAP, then allow it to return to EPAP before squeezing the resuscitator again. (The IPAP should now be set at approximately 10 cm H2O and the EPAP reading should be approximately 4 ± 1 cm H2O for early VPAP II ST-A models, and 2 ± 1 cm H2O for all other models.) 6 Remove the resuscitator from the air tubing and confirm that air flow stops after approximately 10 seconds. If the flow generator begins autotriggering, refer to Section 8 Troubleshooting guide for help in determining the cause of the problem. If the flow generator fails this test, follow the procedures outlined in Section 7 Final test and calibration procedures to do a full test and recalibration of the flow generator, or return the unit to ResMed for service. 10 Alarm test 1 Select Performance Tests>Alarm Test. 2 Follow the instructions on the screen. 3 Record the results in the record of service form on page 9. If the unit fails the Alarm test, follow the procedures outlined in Section 7 Final test and calibration procedures to do a full test and recalibration of the flow generator, or return the unit to ResMed for servicing. 11 Reload clinical settings 1 Select Settings>Set Operating Mode, Pressure and Options. 2 In the Set Operating Mode, Pressure and Options window select File>Read options from file to screen and locate the file with the unit’s clinical settings.

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VPAP™ II LCD Group Service Manual

3 Press the Set button at the bottom of the Set Operating Mode, Pressure and Options window to load the settings into the flow generator.

Set button

Caution

!

If setting up for a particular customer, use the same type of mask and air tubing as used by the customer during pressure setting to ensure that the pressure supplied at the mask is correct. The flow generator will then need to be reset to patient mode: 4 While holding down SW3, SW4 and SW5, turn on the flow generator. This puts the flow generator into Clinical mode. 5 Press SW3 until the LCD cycles through to PATIENT MODE. Press SW4 to activate patient mode. You will be prompted to confirm: press SW4 to answer YES. Patient mode prevents the patient from changing the flow generator’s settings. 12 Fill in Service request form If there are any problems with the flow generator, fill in Appendix A: Service request form Repair the unit if possible (refer to Section 8 Troubleshooting guide). If the unit cannot be repaired return the form and unit to ResMed in Sydney for review and logging. The address may be found on the first page of this manual.

3 General inspection and servicing

15

4

Static Precautions

Warning

!

Prior to disassembly or assembly, make sure that the power is not connected to the flow generator. Integrated circuits (ICs) within the various PCBs can be badly damaged by electrostatic discharge or transient voltages. The following procedures are recommended to avoid component damage: 1 Work benches where handling and repairs are done must have surfaces of suitable conducting material connected via a 1 MΩ resistor to an electrical ground. 2 The area under and also in front of the work bench must be coated with a suitable conductive floor paint, or alternatively covered with a conductive floor mat. The conductive paint coating or floor mat must be connected to an electrical ground. 3 Soldering irons or solder baths must be at the same reference (ground) potential as the work bench. 4 A wrist strap must be worn by service personnel working at the bench. The wrist strap must have a conductive lead (1 MΩ) connected to the bench surface. Alternatively, a heel grounding strap to ground the operator to the floor may be used. (Such a wrist or heel strap should not create an electrical hazard for the wearer). 5 Handling of ICs should be kept to a minimum. If handling is required, avoid directly touching the leads. The recommended procedure is to first touch the container in which the ICs are stored, or the PCB in which they are mounted, before touching the ICs. Service personnel should take every precaution that the items will see the same reference potential when moved. 6 All ICs and PCB assemblies containing ICs should be stored in antistatic bags until use. 7 Service personnel should wear clothing which minimizes the build up of static charges. Cotton is preferable to wool or synthetic fibres. 8 Service personnel should avoid electrostatic build up through the movement of air over plastic material. 9 Plastic materials should wherever possible be kept away from the ICs as they develop and maintain high levels of static charge. 10 Low humidity increases potential static problems. Maintaining humidity levels above 60% is one of the most effective ways to guard against static handling problems.

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VPAP™ II LCD Group Service Manual

5

Replacing major subassemblies This section contains brief instructions and points to be aware of as you replace major subassemblies and reassemble the flow generator.

Warning

!

The VPAP II group of flow generators use a non-isolated power supply. The power supply does not provide any primary/secondary isolation, so ALL circuitry in these flow generators is LIVE at mains potential! Whenever it is necessary to work with the cases opened up and power switched on, you must first connect an isolation transformer between the flow generator and the mains power supply.

Caution

!

Whenever any PCB or any part of the air pathway is replaced, the flow generator must be recalibrated by following the procedures in Section 7 Final test and calibration procedures. Thread cutting screws are used in the flow generator. When replacing a thread cutting screw, turn the screw anticlockwise until it fits into the previously cut thread. Otherwise the original thread may be stripped.

5 Replacing major subassemblies

17

Opening the flow generator 1 Turn the flow generator upside down and remove the seven socket head screws which hold the top case and the bottom case together. 2 Turn the flow generator right-side up again and remove the top case. The Main PCB, motor assembly and power supply are all accessible. To replace the Expansion PCB, first remove the Main PCB. Power supply

Motor assembly

Main PCB

Replacing PCBs Replacing the Power Supply PCB 1 Disconnect the power supply output lead from the Main PCB. 2 Undo the four screws which attach the power supply assembly to the bottom case. Screws

Screws

3 Place the new power supply in the bottom case and use the four screws to fasten it to the bottom case. 4 Attach the output lead to the Main PCB.

Warning

!

18

The power supply is either a POWERBOX 166 (R210-7009 -Type 4,5 & 6) or SKYNET SNP-9089-MR (R210-7076 - Type 7 & 8), and are non-isolated. The power supply does not provide any primary/secondary isolation, so ALL circuitry in the flow generators is LIVE at mains potential!

VPAP™ II LCD Group Service Manual

Whenever it is necessary to work with the cases opened up and power switched on, you must first connect an isolation transformer between the flow generator and the mains power supply. Note:

Both power supplies have only one fuse:

M-205 (5 x 20 mm) 3.15 A, 250 V AC, slow blow UL/CSA type

Replacing the power inlet module 1 Lift the power inlet module out of the retaining slots. 2 Disconnect the blue and brown wires from the module. 3 Take the replacement power inlet module and connect the blue and brown wires from the power supply, as shown below:

Brown wire Blue wire

5 Replacing major subassemblies

19

4 Place the power inlet module back in the retaining slots, with the wires closest to the side of the bottom case.

Replacing the inline fuse 1 To replace the fuse, twist and pull open the fuse cartridge located next to the blower housing.

Fuse cartridge

2 Remove the old fuse and replace it with the new fuse. 3 Close the cartridge.

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VPAP™ II LCD Group Service Manual