Semi Stand-By To Active 32” Lcd Lpl Scanning Backlight Flowchart - Philips 42PF9731D Service Manual

Service Modes, Error Codes, and Fault Finding
The assumption here is that a fast
toggle (<2s) can only happen during ON-
>SEMI ->ON. In these states, the Viper is
still active and can provide the 2s delay.
If the transition ON->SEMI->STBY->SEMI-
>ON can be made in less than 2s, we
have to delay the semi -> stby transition
until the requirement is met.
Figure 5-10 "Semi Stand-by" to "Active" 32" LCD LPL Scanning Backlight flowchart
32" LCD LPL scanning 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
Initialize audio and video processing IC's and
functions according needed use case.
Wait until QVCP generates a valid lvds output
clock.
Switch on 12V LCD supply
(LCD-Power-on)
Start to apply valid interface signals to the module (LVDS) within a
time frame of min. 17.5ms to max. 67.5ms after supply switch on.
In implementation, use 25ms, this makes it compatible with 32"Sharp
(t=17.5ms is the supply switch-on delay taken into account)
Switch off backlight (FMS scan rate conversion interface) to
prevent backlight to freerun after preheating phase.
Set scanning backlight to Normal scanning using the
FMS scan rate conversion interface.
Switch off RGB blanking
Switch on LCD lamp after valid, stable video, corresponding
to the requested output is delivered by the Viper
Switch Audio-Reset and sound enable low and demute
(see CHS audio LdspMute interface).
Active
BJ2.4U/BJ2.5U LA
action holder: MIPS
action holder: St-by
autonomous action
G_15910_009.eps
5. EN 25
230606