“Semi Stand-By” To “Active” Flowchart (Led Backlight) - Philips Q549.2E LA Service Manual

Service Modes, Error Codes, and Fault Finding
Constraints taken into account:
- Display may only be started when valid LVDS output clock can be delivered by the AVC .
- Between 5 and 50 ms after power is supplied, display should receive valid lvds clock .
- minimum wait time to switch on the lamp after power up is 200ms.
The assumption here is that a fast toggle (<2s)
can only happen during ON -> SEMI -> ON. In
these states, the AVC is still active and can
provide the 2s delay. If the transition ON -> SEMI-
>STBY->SEMI->ON can be made in less than 2s,
the semi -> stby transition has to be delayed
until the requirement is met.
CPipe already generates a valid output
clock in the semi -standby state: display
startup can start immediately when leaving
the semi-standby state.
The higher level requirement is that audio and
video should be demuted without transient
effects and that the audio should be demuted
maximum 1s before or at the same time as the
unblanking of the video.
The higher level requirement is that the
ambilight functionality may not be switched on
before the backlight is turned on in case the
set contains a CE IPB inverter supply.
Figure 5-8 "Semi Stand-by" to "Active" flowchart (LED backlight)
Semi Standby
Wait until previous on-state is left more than 2
seconds ago. (to prevent LCD display problems)
Assert RGB video blanking
and audio mute
Switch on the display by sending the OUTPUT-
ENABLE (I²C) command to the LED DIM panel
wait 250ms (min. = 200ms)
TBC in def. spec
Switch on LCD backlight
(Lamp-ON)
Wait until valid and stable audio and video , corresponding to
the requested output is delivered by the AVC.
Switch Audio-Reset low and wait 5ms
Release audio mute and wait 100ms before any other audio
handling is done (e.g. volume change)
Switch on the Ambilight functionality according the last status
Q549.2E LA
action holder: AVC
action holder : St-by
autonomous action
Initialize audio and video
processing IC's and functions
according needed use case.
unblank the video.
settings.
Active
I_17660_128.eps
5. EN 23
140308
2009-May-08