Figure 3: Typical Error Code Display - Nellcor OxiMax NPB-40 Service Manual

Troubleshooting
Condition
The NPB-40 does not turn on when the
• The
Power
depressed.
• The batteries are missing.
• The batteries are installed incorrectly or
they are backwards.
• The batteries are at or near a voltage too
low for the NPB-40 to operate.
• The sensor is defective.
• The front panel keypad is defective.
• Flex circuit between the front panel and
the CPU PCB is disconnected.
34
If an error code is shown on the NPB-40 front panel display, see Figure 3,turn the
NPB-40 off, wait ten seconds, then turn the NPB-40 on. This clears recoverable
errors encountered by the NPB-40. If the error code still persists, refer to Table 4
for the indicated failure.

Figure 3: Typical Error Code Display

Once you have performed the recommended action, reassemble the NPB-40, refer
to Performance Verification on page 15, and conduct a performance verification
before returning the NPB-40 to service. If the symptom persists continue
troubleshooting.
Table 3:
button was not fully
Troubleshooting Guide
Recommended Actione
button is pressed.
Power
Fully press the button.
Power
Open the battery compartment and if batteries are missing
install new batteries. Refer to the NPB-40 Operator's
manual.
Open the battery compartment and if batteries are not
installed correctly, remove and reinstall the batteries. Refer
to the NPB-40 Operator's manual.
Install new batteries. Refer to the NPB-40 Operator's
manual.
Replace the sensor.
Caution: Unlock J3 before attempting to
remove flex circuit conductor.
Open the NPB-40, disconnect the front case from J3 on the
CPU PCB and connect an ohmmeter between the flex circuit
conductor for J3, pin 5 and the conductor for J3, pin 3.
Observe a short when the
open when not pressed. If incorrect, replace the front case.
See Front Case Assembly Replacement on page 49.
If the button functions correctly, replace CPU PCB.
Power
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.
button is pressed and an
Power