Table 5-6: Serial Port Problems - Nellcor NPB-190 Service Manual

Section 5: Troubleshooting
5.6.5 Serial Port
5-6
Table 5-6 lists symptoms of problems relating to the serial port and
recommended actions. If the action requires replacement of the PCB, refer to
Section 6, Disassembly Guide.

Table 5-6: Serial Port Problems

Condition
1. No printout is being
received.
2. The Nurse Call function
is not working.
Recommended Action
1. The unit is running on battery power.
Connect to an AC source. If the AC indicator
is not on see section 5.6.1.
2. The monitor's baud rate does not match the
printer. Change the baud rate of the monitor
following instructions in section 4.3.7.
3. Check connections between serial port and
printer (see section A3).
4. If the condition still persists, replace the UIF
PCB.
1. The unit is running on battery power.
Connect to an AC source. If the AC indicator
is not on see section 5.6.1.
2. Verify that connections are made between
pins 5 or 10 (GND) and 11 (Nurse Call) of
the serial port.
3. Verify that output voltage between ground
pin 5 or 10 and pin 11 is -5 to -12 VDC (no
alarm) and +5 to +12 VDC (during alarm).
4. If the condition still persists, replace the UIF
PCB.