Table 6: Power Problems - Nellcor OxiMax N-550 Service Manual

N-550

Table 6: Power Problems

Condition
Battery Low indicator
lights steadily while
-
N 550 is connected to
AC and battery is fully
charged.
-
The N 550 does not
operate when
disconnected from AC
power.
Battery Low indicator
on during DC operation
and an alarm is
sounding.
Recommended Action
Ensure that the N-550 is plugged into an operational
AC outlet and the AC indicator is on.
Check the fuses. The fuses are located in the Power
Supply PCB as indicated in Separating Top and Bottom
Cases on page 56. Replace if necessary.
Open the N-550 as described in 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 battery 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 power supply if above values are not met.
Check the cable connection between the Top Enclosure
and the Front Panel PCB. If the connection is good,
replace the Front Panel PCB. See Front Case
Disassembly on page 58.
The battery may be discharged. To recharge the battery,
refer to Battery Charge on page 8. The N-550 may be
used with a less than fully charged battery, but with a
corresponding decrease in operating time from that
charge.
Replace the battery as indicated in Battery Removal on
page 68.
There are 15 minutes or less of usable charge left on the
- N-550
N 550 battery before the
if possible, cease use of the N
connect it to an AC source and allow it to recharge
(approximately 11 hours). The N
be used while it is recharging. (A full recharge of the
battery while the N-550 is being used takes 12 hours.)
Troubleshooting
shuts off. At this point,
-
550 on battery power,
-
550 may continue to
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