Table 5-6: Serial Port Problems - Mallinckrodt NELLCOR NPB-195 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 is not
working.
Recommended Action
1. The unit is running on battery power.
Connect to an AC source.
2. The monitor's baud rate does not match the
printer. Change the baud rate of the monitor
following instructions in paragraph 10.2.
3. If the condition still persists, replace the UIF
PCB.
1. The unit is running on battery power.
Connect to an AC source.
2. Verify connections are made between pins 10
(GND) and 11 (nurse call) of the serial port.
3. Verify output voltage between ground pin 10
and pin 11 is -3 to -10 VDC (no alarm) and
+3 to +10 VDC (during alarm)
4. If the condition still persists, replace the UIF
PCB.