NELLCOR PURITAN BENNETT Symphony N-3000 Service Manual page 28

Section 3: Performance Verification
3-18
Battery
Power
connector
7. Turn the monitor on by pressing the ON/STANDBY button.
8. When the power-on self-test is complete, disconnect the power connector
from the battery. Verify that a shrill, beeping alarm is emitted from the
speaker. If no alarm sounds, check the functionality of the lithium
backup battery as indicated in paragraph 4.3.9, menu item 18.2 of the
service mode. The battery should measure approximately 3 volts. If the
battery is good, replace the UIF PCB as indicated in paragraph 6.8.
9. Reconnect the power connector to the battery. The alarm is silenced and
the monitor powers back on.
10. Turn the monitor off by pressing the ON/STANDBY button.
11. Replace the battery in the battery bracket and reconnect the battery
cover.
Battery bracket
Figure 3-5: Speaker Test
Battery cover