Philips Fm2 Service Manual

							Service Menu
Chapter 4 - Power-up Default Settings and the Service Menu
29
System A/D Values
For the end user or service personnel, the system A/D values require no 
interpretation.
The A/D screen displays the current value of each analog-to-digital
(A/D) channel in volts. The A/D channels read DC voltages, for example, power 
supply voltages and battery voltage. The A/D values displayed are static, being 
acquired when the screen is first displayed.
None of the displayed values may be changed or reset in this screen.When in the 
A/D screen, the 
Return item is always highlighted; a press of the wheel will 
return the user to the Service Menu. Rotating the wheel while in the A/D screen 
will have no effect. The A/D Values screen appears as follows:
Figure 3 System A/D Values
Note—The  screenshot above shows untypical system A/D values that are 
not representative of normal operation. 
						

							Service Menu
30Chapter 4 - Power-up Default Settings and the Service Menu 
						

							Chapter 5 - Troubleshooting31
5
Troubleshooting
General
This section provides a guide for qualified service personnel in locating the 
possible cause of an apparent malfunction of the monitor or its accessories. Use 
of built-in diagnostics, flow charts, and step-by-step procedures are provided as 
aids in the troubleshooting process.
The chapter leads you to a probable field replaceable assembly or component. 
Items that are serviceable only at the factory are also identified, as well as 
instructions for their return for repair/replacement.
The initial analysis determines whether the apparent malfunction is caused by a 
replaceable accessory, or by a replaceable assembly within the monitor case.  
						

							General
32Chapter 5 - Troubleshooting
Initial Trouble Diagnosis
The first step in diagnosing a possible malfunction is to duplicate, if possible, 
the symptoms of the reported malfunction. Thereafter, it is important to 
categorize the problem as either one of two types, as illustrated in Figure 4. They 
are:
 Totally inoperative condition, or
 Degraded operation.
The totally inoperative condition is indicated by the failure of the monitor to 
respond to the power ON front-panel action, or by complete loss of monitoring 
functions during operation. Contact your local Agilent Response Center.
Degraded operation performance might be indicated by the appearance of 
artifacts in the display, or by gaps in the pixel display, by intermittent actions, or 
by obviously inaccurate measures of fetal activity, etc.
Figure 4 Diagnosing Malfunction - Initial Diagnosis 
						

							Power Problem Diagnosis
Chapter 5 - Troubleshooting
33
Power Problem Diagnosis
Diagnostic Flow Chart
The flow chart of Figure 5 shows a sequence of actions and decisions you can use 
after the initial diagnosis of a “total failure” as a power supply or display 
problem.
Note—If the apparent “total failure” is caused by a malfunctioning display 
backlight, you may see a faintly lit display with the appropriate Power-On 
Self Test message. The troubleshooting under these circumstances is 
described in this section.
Figure 5 Power Diagnosis - Power Supply or Display  
						

							Power Problem Diagnosis
34Chapter 5 - Troubleshooting
Diagnostic/Repair Actions
Examine
Display
IntenselyReduce background room illumination. If only the back light fluorescent tube 
or its high voltage driver has failed, the display may be faintly visible.
Refer to page 50 for removal procedures.
Replace
BatteryRefer to page 43.
Exchange the
MonitorIf the display is not at all visible, and there is total failure, exchange the monitor.  
						

							Monitoring Degradation Problems
Chapter 5 - Troubleshooting
35
Monitoring Degradation Problems
Diagnostic Flow Chart
Figure 6 illustrates a logical sequence of troubleshooting diagnostics when the 
monitor appears to be operative, but the displayed results are suspect for any 
number of reasons. The resulting diagnosis will result in replacing either the 
monitor or the transducers.
Figure 6 Monitoring Degradation, Diagnostic Flow Chart 
						

							Monitoring Degradation Problems
36Chapter 5 - Troubleshooting
Diagnostic Repair Actions
Describe
Degraded
PerformanceExamine the display after an apparently successful power up sequence and self-
test.
Consider, first, the appearance of artifacts, gaps, or general quality of the display.
Note the values being reported in the numerical frames (FHR(s)) and TOCO). 
Are they clearly unreasonable?
Swap
TransducersUse a spare transducer that is free of defects and meets factory specifications. At 
facilities where more than one monitor is installed, it may be convenient to 
borrow a transducer that is working satisfactorily with another monitor.
Exchange the
MonitorIf the monitoring problems persist, or there is total failure, exchange the 
monitor. 
						

							Chapter 6 - Disassembly/Reassembly Guide37
6
 Disassembly/Reassembly Guide
Warning
Performance verification: do not place the monitor into operation after 
repair or maintenance has been performed, until all performance tests and 
safety tests listed in Chapter 8 of this service manual have been performed. 
Failure to perform all tests could result in erroneous monitor readings, or 
patient/operator injury.
Warning
Energized circuits are accessible with the covers open. Do not work on the 
monitor with the covers open. Only qualified service personnel should 
open or disassemble the monitor.
Introduction
Warning
Before attempting to open or disassemble the monitor, disconnect the 
power supply from the monitor.
Warning
High voltage is generated by the LCD backlight driver. Do not operate the 
monitor with the covers open. 
						

							How to Use this Chapter
38Chapter 6 - Disassembly/Reassembly Guide
Caution
Observe ESD (electrostatic discharge) precautions when working within 
the unit.
Caution
Important for disassembly! When disassembling the monitor, make sure 
that the battery leads are disconnected. Otherwise, it is likely that circuit 
damage will occur.
The monitor can be disassembled down to all major component parts, 
including:
PCBs
battery
cables
function buttons
chassis enclosures
Remember to store all screws, nuts, washers and other parts in a safe place for 
later refitting.
How to Use this Chapter
The step-by-step procedures that are used to access replaceable parts of the 
monitor are illustrated in the Disassembly sections which follow. These describe 
and photographically illustrate procedures for disassembling the monitor to 
enable removal and replacement of suspected defective assemblies and 
components.
The monitor consists of two main assemblies:
The front case assembly
The rear case assembly
The main PCB assembly is separable from the front case assembly.