Nellcor NPB-75 Service Manual page 26

Table 5-1: Troubleshooting Guide (Continued)
Symptom Probable Cause
The unit does not The wall socket is not
turn on when the receiving power or is
ON/OFF button defective.
is switched ON
when the
monitor is
connected to
mains line
power.
The AC adapter is
defective.
A CO
is defective.
One or more The keypad is defective.
buttons on the
upper or lower
keypad do not
work.
A CO
has failed.
No information The contrast default
is displayed on value is set too low or
the LCD. high.
An LCD component has
failed.
A CO
has failed.
LCD Backlight The Power
does not come on Management option is
when the unit is set at LOW .
placed in a dark
environment.
An LCD component has
failed.
A CO
has failed.
Corrective Action
Check the wall socket
for power supply or
mechanical defects. If
necessary, use a
different wall socket.
Replace with new AC
adapter.
board component Replace with a new
2
CO
Inspect the keypad for
cracks, deformations
or other damage.
Replace with a new
keypad.
board component Replace with a new
2
CO
Check the contrast
value in the Service
Mode using the
Contrast Cal.
option and correct
accordingly.
Replace with a new
LCD.
board component Replace with a new
2
CO
Refer to the monitor's
operator's manual to
change the Power
Management option
to NORMAL or
HIGH .
Replace with a new
LCD.
board component Replace with a new
2
CO
Section 5: Troubleshooting
board.
2
board.
2
board.
2
board.
2
5-3