Philips 32PF9968/10 Service Manual page 24

EN 24 5. LC9.1A LA
POWERDOWN SEQUENCE
The following figure shows the power-down sequence
flowchart:
POWER_DOWN INT
based on falling
POWER_DOWN INT
edge trigger
Write Protect Flash and
Wait for
impending
Power Off
Figure 5-13 Power-down flowchart
The power-down condition is detected by the MT5392
POWER_DOWN signal which is an interrupt pin. A "low" level
on this line signifies that power-down is detected. The two
major activities that occur over this operation is the muting of
audio output and write protecting the system flash and
EEPROM.
DC PROTECTION
The following figure shows the DC_PROT interrupt flowchart:
Mute Audio Output
DC Protection
[Protection]
Figure 5-14 DC Protection flowchart
5.6.10 SSB replacement
Follow the instructions in the flowchart in case a SSB has to be
swapped.
2009-Apr-10
Service Modes, Error Codes, and Fault Finding
START
MT5392 Detects
Reconfirm
POWER_DOWN
= LOW?
Yes
Mute Audio Output
Note: To
No
Avoid False
Triggering
System EEPROM
System Idle
END
18490_200_090408.eps
START
Check
DC_PROT = LOW
for 3 sec?
Yes
Note: To
No Avoid False
Triggering
Log Error Code
Go to STANDBY
END
H_17740_037.eps
090408
240108