Nellcor N-180, Manual

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N-180 Pulse Oximeter Service Manual
5-2
Interpreting Symptoms
A monitor that malfunctions typically displays clear symptoms. These symp-
toms are listed in applicable table columns labeled
Symptom in troubleshoot-
ing charts in this section. Alternately, when the symptoms are complicated
and interrelated, a decision tree is used to simplify presenting the informa-
tion. Follow the symptom descriptions in a given tree and then accomplish the
applicable repair strategy as described in the accompanying table.
You may encounter a malfunction that has multiple causes. In such cases,
work from left to right in the decision tree, as usual. Correct the first problem
listed in the tree, then correct the next problem. Generally, the first problem
listed is the most common or the easiest to verify. If you experience a symp-
tom not listed in this section, please contact Nellcor Technical Service in
Hayward, California.
Status Messages
Status messages appear in the SATURATION display immediately after the
ON /STDBY switch is set to ON . Status messages for seven error categories
are given in table 5-1.
Table 5-1: Status Messages by Category
Symptom Probable cause Action
Err 1 (error 1) Defective monitor Contact qualified service personnel
Defective data memory Replace the CPU PCB .
Err 2 (error 2) Defective monitor Contact qualified service personnel
Defective program memory Replace the CPU PCB .
Err 3 (error 3) Defective monitor Contact qualified service personnel
Defective connection between the LED
Drive PCB and the LED PCBs.
Check the connectors labeled CN on
both PCBs. (Refer to Section 6 for a
wiring diagram.)
Defective display components on the
LED PCB .
Replace LED PCB
Defective display decoder and driver
ICs on the LED Drive PCB.
Replace the LED Drive PCB
Defective CPU PCB. Replace CPU PCB
Err5 over run Slow data buffer Set Power switch to off and then to on. If
problem persists, replace CPU PCB.
Err6 over run Receive buffer for MP-203 oximetry
module
Set Power switch to off and then to on. If
problem persists, replace CPU PCB.
Err 7 (error 7) Communication error. Over run of
transmission buffer for data to MP-
203 oximetry module
Replace CPU PCB
Front Panel Display
The front panel LED
S
are automatically tested each time the monitor
ON /STDBY switch is set to ON . This test takes place quickly and you
probably cannot spot a missing segment of an LED display while this test is
running (but if an LED is bad the test fails regardless). To manually check
the LED display :
1. Press the HIGH SAT push-button and set the ON /STDBY switch to ON .