Nellcor OxiMax NPB-40 Service Manual page 43

Condition
• A CPU PCB Component has failed.
One or more keys on the front panel keypad does not work.
• The front panel keypad is defective.
• Flex circuit between the front panel and
the CPU PCB is disconnected.
• A CPU PCB Component has failed.
• CPU PC has failed.
One or more display segments does not work.
• A display PCB component has failed.
• The Display PCB is defective.
The speaker does not sound for pulse rate or alarms.
• The speaker is turned off.
• The holes for the speaker on the back of
the NPB-40 are blocked.
• The external output port on the CPU
PCB has failed.
• The speaker on the Display PCB has
failed.
Pulse rate and %SpO
• The SpO sensor is not connected
2
properly.
• The SpO sensor has failed.
2
• The Display PCB is defective.
NPB-40
Table 3:
Troubleshooting Guide
Recommended Actione
Inspect the CPU PCB components and circuit board for
cracking, burning, or damage and replace the CPU PCB if
any are found. See CPU PCB or Display PCB Replacement
on page 46.
Open the NPB-40, disconnect the front case from J3 on the
CPU PCB and connect an ohmmeter lead to the flex circuit
conductor for J3, pin 3 and individually connect the other
ohmmeter lead to each conductor for the buttons. Refer to
the front panel schematic diagram (**). Observe a short
when the button is pressed and an open when the button is
not pressed.
If incorrect, replace the front case. See Front Case Assembly
Replacement on page 49.
If correct, replace the CPU PCB. See CPU PCB or Display
PCB Replacement on page 46.
Inspect the flex circuit and reconnect if the flex circuit is
loose. See Separating the Front and Back Cases on page 44.
Inspect the CPU PCB components and circuit board for
cracking, burning, or damage and replace the CPU PCB if
any are found. See CPU PCB or Display PCB Replacement
on page 46.
Replace the CPU PCB with a known good PCB. See CPU
PCB or Display PCB Replacement on page 46.
Inspect the Display PCB for cracking, burning, or damage
and replace the Display PCB if any damage is found. See
CPU PCB or Display PCB Replacement on page 46.
Replace the Display PCB if any damage is found. See CPU
PCB or Display PCB Replacement on page 46.
Turn the NPB-40 off then on.
Clear the holes for the speaker on the back of the NPB-40.
Replace the CPU PCB with a known good PCB. See CPU
PCB or Display PCB Replacement on page 46.
Replace the Display PCB with a known good PCB. See
CPU PCB or Display PCB Replacement on page 46.
value is not shown and the NPB-40 is turned on.
2
Connect the SpO
Connect the SpO
Directions for Use.
Replace the SpO
Replace the Display PCB with a known good PCB. See
CPU PCB or Display PCB Replacement on page 46.
(Continued)
Caution: Unlock J3 before attempting to
remove flex circuit conductor.
sensor to the NPB-40.
2
sensor to the patient. See the sensor
2
sensor with a known good sensor.
2
Troubleshooting
35