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EN 22
5.
LC9.2A LA
5.6.9
Start-up/Shut-down Flowcharts
On the next pages you will find start-up and shut-down
flowcharts, which might be helpful during fault finding.
POWER STATES
In this chassis, there are six possible power states as follows:
•
Power OFF
•
Power ON
•
STANDBY
•
SEMI-STANDBY
•
Special Panel Mode
•
PROTECTION
Figure 5-10 Power States
POWER OFF
In "Power OFF" mode, the system is completely switched "off"
from AC mains. When AC power is applied, the system checks
for last status. Depending on the last standby status stored in
the system EEPROM, this mode can then transit to "ON" or
"STANDBY" mode.
ON
This is the normal operating mode, indicated by the "on" LED.
All the power supply lines are available and depending on the
sub-mode, all the circuits in the system may be active. From
this mode it shall be possible to transit to "STANDBY" and
"PROTECTION" mode, or to "Power OFF" mode if AC mains
are switched "off". The sub-modes are:
•
Active Mode (Normal Consumer Mode)
•
Service Modes
•
Panel Modes
•
Factory Modes
STANDBY
The total power consumption of the system in this mode shall
be equal or less than 150 mW. This state is indicated by white
LED when AC mains is switched "on". Only the standby
controller is operational in this state, where only +3V3stby
power supply is available. From this mode it shall be possible
to transit to the "ACTIVE" or "Power OFF" mode if AC mains are
switched "off".
SEMI-STANDBY
The semi-standby state is required to perform the following
tasks:
•
AmbiLight wakeup control
•
PBS SemiStandby.
2010-Jul-01
Service Modes, Error Codes, and Fault Finding
18490_204_090409.eps
090409
SPECIAL PANEL MODE
The Special Panel Mode is only used during manufacturing
process to program the system EEPROM. In this mode, the
SDA0 and SCL0 ports of MT5392 are set to high impedance
after SDM and PANEL pins are both detected as "low" during
start-up. This mode can be exited using a power recycle.
PROTECTION
This state is entered when an error has been detected at start-
up or in the "ACTIVE" mode. All switched power supply lines
are turned "off" with only +3V3stby remaining "on"; similar to
"STANDBY" mode. This state is indicated by the blinking red
front LED with the blinking sequence denoting the type of error
detected.
When the system enters the protection mode due to a critical
error, it should be turned "off" and the failure cause needs to be
resolved. The system will function normally again after
performing a power recycling once all protection causing
failures have been resolved.
START-UP SEQUENCE
There are two cases of start-up sequences, namely:
•
AC On and
•
Standby Wake-up.
See also
Figure
5-11.
AC ON
In the case of start-up from AC mains, all PSU voltages start to
turn "on" as the hardware default of the active "low" STANDBY
(controlled by Standby Controller STANDBY signal) signal to
the PSU is pulled "low" with respect to ground.
The MT5392 starts running boot loader once the hardware
reset circuit is released. The system will then check the last
standby status from the system EEPROM to determine
whether to complete the system start-up (load image, turn on
the audio, display etc) or proceed to standby and wait for wake-
up command from user. The Standby Controller then proceeds
to verify the power status of the +12V and sends the system to
protection in case of any failures. Special Panel, SDM, and
PANEL modes are detected as well.
STANDBY WAKEUP
When the system receives a command to wake-up from
standby, the Standby Controller sets the STANDBY signal
"low" to turn "on" the switched power, and similarly detects for
the presence of +12V. The MT5392 waits for +3V3_SW to be
available before loading its image. The significance of this
voltage detection is due to the flash is also being powered by
the same mentioned voltage.
The following figure shows the start-up flowchart for both "AC
On" and "Standby Wake-up":
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