Siemens SC 7000 Service Manual page 98

Service Manual
8 LCD Display Malfunction
Table 5-6 LCD Display Malfunction
Symptom(s)
Display backlight
intensity does not vary
with change in ambient
light
> 17 inoperative pixels
("stuck" ON or OFF) .
Areas of display
missing or color
contaminated
Backlight fails to
provide sufficient and
consistent background
illumination for the
LCD display.
9 Isolating Cable Malfunctions
82
.
Possible Cause(s)
Sensor malfunction
Front Bezel PC Board
malfunction
LCD screen malfunction
LCD Display malfunction
Front Bezel PC Board
malfunction
Graphics Processor on
Main Processor PCB
malfunction
Backlight defective
Front Bezel PC Board
malfunction
Main Processor PCB
malfunction
In general, the troubleshooting and repair approach for cable malfunctions
is to use a known input signal for any given parameter, and then replace a
cable or sensor found to be malfunctioning. Cable malfunctions, including
those associated with connectors on the cables, generally fall into one of
three cagegories -- Open circuits, Short circuits, and Intermittent conditions
Open circuits and short circuits manifest themselves as a loss of signal.
Software in the Monitor senses the loss, and generates an error message
such as "ECG Leads Off" and "SpO2 Transparent." Typically, short circuits
result in software resets.
An intermittent condition manifests itself as noise on the signal. The source
of the noise can often be isolated by removing the signal and shorting the
input(s) to the cable. Then flex along the cable, particularly at connectors,
while watching for noise indications on the monitor display.
Siemens Medical Systems, EM-PCS, Danvers
NOT A CONTROLLED DOCUMENT
SC 7000 and SC 9000XL Patient Monitors
Troubleshooting and Remedial Action
1. Assure that monitor is being powered by CPS/IDS or
PSL, and intensity control is set to "Auto" mode.
2. • If in brightly lighted environment, cover ambient
sensor on upper right corner of front bezel.
• If in dimly lighted environment, shine light source
directly on ambient sensor on upper right corner of
front bezel.
3. If no change in display intensity, replace Front Bezel
PC Board. If problem persists, replace Main
Processor PCB Subassembly.
4. If problem persists, contact TSS in Solna or Danvers.
Replace Front Bezel Subassembly.
1. Using VGA connection cable and interface plate,
connect external VGA display to X7 on interface
plate.
2. • If external display exhibits similar problem, replace
Main Processor PCB Subassembly.
• If external display OK, replace Front Bezel
Subassembly. If problem persists, replace Main
Processor PCB Subassembly.
3. If problem persists, contact TSS in Solna or Danvers.
1. Replace backlights.
2. If problem persists, replace Front Bezel PC Board.
3. If problem persists, replace Main Processor PCB
Subassembly.
4. If problem persists, contact TSS in Solna or Danvers.
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