Table 7: Button Problems - Nellcor OxiMax N-550 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 55.
Symptom
-
The N 550 turns on and
responds to some, but
not all, buttons.
-
The N 550 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 68.
Open the N-550 as described in Monitor Disassembly
on Separating Top and Bottom Cases on page 56.
Verify the power supply's output to the battery while on
AC. Disconnect the battery leads from the power
supply and connect a DVM to them. The voltage
measured should be 19.8 VDC to 20.2 VDC and the
current should be 50 mA to 210 mA. Replace the power
supply if the above values are not met. See Power
Supply Removal on page 64.

Table 7: Button Problems

Recommended Action
Replace Top Housing assembly. See Separating Top
and Bottom Cases on page 56.
Replace Front Panel PCB. See Front Case
Disassembly on page 58.
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 62.
Replace the Front Panel PCB. See Front Case
Disassembly on page 58.