Table 7: Button Problems - Nellcor OxiMax N-550B Service Manual

Troubleshooting
Buttons
46
Table 6: Power Problems (Continued)
Condition
Battery does not
charge.
Table 7 lists symptoms of problems relating to nonresponsive buttons and
recommended actions. If the action requires replacement of a PCB, see
Disassembly Guide on page 53.
Symptom
-
The N 550B turns on
and responds to some,
but not all, buttons.
-
The N 550B turns on,
but does not respond to
any of the buttons.
Recommended Action
Replace battery if it is more than 2 years old.
Replace the battery as indicated in Battery Removal on
page 66.
Open the N-550B as described in Separating Top and
Bottom Cases on page 54. Verify the power supply's
output to the battery while on AC. Disconnect the
battery leads from the battery and connect a DVM to
the battery leads. The voltage measured should be 13.8
VDC to 14.2 VDC and the current should be 170 mA to
300 mA. Replace power supply if above values are not
met.

Table 7: Button Problems

Recommended Action
Replace Top Housing assembly. See Separating Top
and Bottom Cases on page 54.
Replace Front Panel PCB. See Front Case
Disassembly on page 57.
Check the connection between the Main PCB and the
Front Panel PCB.
Replace the main PCB. See Monitor Disassembly on
Main PCB Removal on page 60.
Replace the Front Panel PCB. See Front Case
Disassembly on page 57.