Fisher & Paykel MR700, MR720, MR730, MR480 technical manual Servicing Information

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7.0SERVICING INFORMATION _____________________________________

7.1INTRODUCTION

This section provides information for servicing the MR730/720/700/480 Humidifier. The electronic circuitry is contained on two separate circuit boards, the power board and control board.

Please note the following:

•Follow ESD precautions when handling circuit boards.

•After replacing or modifying a circuit board, go through the calibration and performance tests outlined in § 5 and 6.

•After any repair involving opening of the humidifier, go through the electrical safety tests outlined in Appendix B2.

•When replacing any screws, refer to torque settings in § 7.6.

7.2PRINTED CIRCUIT BOARD REMOVAL

7.2.1CONTROL PCB

The front panel and heaterplate assembly is separated from the humidifier body by removing the 4 fixing screws from the rear of the humidifier body. The front panel assembly can now be moved aside and the two ribbon cable connectors (J1 and J2) disconnected from the rear of the control board. If the front panel is now positioned face down the three plastic retaining latches protruding through the board can be moved in the appropriate direction to release the board. This is facilitated if a slight upward finger pressure is maintained on either edge of the board, when the latches release, the board will pop up leaving the push on control knobs behind in the front panel.

7.2.2POWER PCB

Separate the case front from the humidifier body and disconnect the two ribbon cable connectors joining the Power PCB and Control PCB (J1 and J2). Cut the cable tie holding the heaterplate and chassis wires together.

The power board and heat sink assembly can now be removed by flexing the case sides away from the top edge of the board and moving the board forward slightly to disengage from the case. The board should now be lifted slightly to clear the lower retaining guides and moved further forward to gain access to the various wiring harness connectors which can now be detached. Before removing the PCB, unscrew the mains cord connections and cut the cable tie holding the mains cord in place.

7.3COMPATABILITY

7.3.1HARDWARE COMPATABILITY

∙If a revision D or earlier power or control PCB needs to be replaced, then both PCBs need to be upgraded together to ensure correct performance. Revision F and later PCBs can be replaced individually.

∙To upgrade both PCBs and the software use a PCB service upgrade kit. The part numbers to order are as follows:

Model

Part number

Model

Part number

MR480

043040791

MR720

043040793

MR700

043040792

MR730

043040794

∙For humidifiers with Rev F or later PCBs, you will only be required to purchase individual boards for repairs (as detailed in sect. 8.9).

∙If a revision H or later power PCB needs replacing, the replacement power PCB must also be revision H or later.

Replacing revision F or earlier power PCB MR700/720/730

Ref. 185040646 MR730/720/700/480 Technical Manual ¯ Revision F ¯ Issued March 2001

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Contents Auckland, New Zealand D E L S MR730 MR720 MR700 MR480National Office Revision F changes Section Description of ChangeContents Performance Check MR480 Dual Probe Temperature Test10.1 Power PCB Harness Connection DiagramMaintenance Schedule B1.1 Maintenance Schedule ChecklistAppendix D Models MR730/720/700 MR700 Series General SpecificationsRSD EOHSET TOPMR700 Series Humidifiers with Version 1.0 Software Operating Controls and ModesStandby Button MR700/720/730 only 1 MR700/MR730 ALL Software VERSIONS, MR720 Version 1.0 only 2 MR720 Version 2.0, 3.0 SoftwareAlarms and Indicators Version 3.0 Software Version 1.0 and Version 2.0 SoftwareAudio Alarm Circuit Operation Power Line Interrupt Revisions D/F Pcbs Revision H and J Pcbs For models with Revision D PCB and earlier CalibrationPage Performance Check Alarms Check MR700/720/730 Dual Probe Temperature Test Servicing Information Replacing revision F or earlier power PCB MR700/720/730Replacing revision F or earlier power PCB MR480 Fault Location SCHEMATICS, Part Lists and Mechanical Drawings Power Board Control Board Component Layout Revision F PCB Page This page Left Blank Circuit Diagrams Revision H and J PCB Control PCB Circuit Diagrams Revision H and J PCB Power PCB Circuit Diagrams Revision F PCB Control PCB Circuit Diagrams Revision F PCB Power PCB LED6,LED7 LED8,LED9,LED10 DSP1, DSP2, DSP3LED1, LED3 LED2,LED4, LED5,LED11VR4 SW5SPK1 VR1Fuse fast acting 2 a 20 × 5 mm for 230 999830009 MR480AGM Exploded Diagrams MR480 10.3 MR730/720/700 Mechanical Parts MR720ASU Exploded Diagrams MR730/720/700 Heaterplate Assembly Parts MR730/720/700/480 Page PCB Identification Diagram Power PCB Harness Connection Diagram Date Change First Serial Number Comments Affected Product Change HistoryYear Model Code Serial Number AAA XxxxxOFF Appendix aA2.3 Integral Display Error MessagesEP4 EP1EP2 EP3Third Byte First ByteSecond Byte A5.4 Serial Data Interface Connector Appendix B B1 Maintenance ScheduleElectrical Safety Checks as required Photocopy and File in Maintenance RecordsPossible cause Action to take Appendix CHigh Temperature C1.6 C1.5LED on Check Voltage Rating Of Unit Appendix D Cleaning instructionsAppendix E Setup NotesDynamic Test Sequence MR730/720/700 Dynamic Test Procedure MR480
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