Philips BJ3.1E LA Service Manual page 26

EN 26 5. BJ3.1E LA
LCD LPL 26" WX2- SLB2 / 32 "W01- SL06 / 37"WX1- SL04 /
42"WU02-SLB1 / 42" WX3- SLA1 / 42" WX2-SLA1 / 47" WU1-SLC2
Constraints taken into account:
- Display may only be started when valid QVCP output clock can be delivered by the Viper.
- 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.
- To have a reliable operation of the backlight, the backlight should be driven with a PWM
duty cycle of 100% during the first second. Only after this first second, the PWM may be set
to the required output level (Note that the PWM output should be present before the
backlight is switched on). To minimize the artefacts, the picture should only be unblanked
after this first second.
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
Service Modes, Error Codes, and Fault Finding
Wait until previous on-state is left more than 2
seconds ago. (to prevent LCD display problems)
requirement is met.
Initialize audio and video processing IC's and
Rewrite Pacific register 0x03 (output format) with TcuUpdate: this
command is sometimes not processed properly by the Pacific at
initialisation time, resending it here solves the issue.
Wait until QVCP generates a valid output
Start to apply valid interface signals to the module (LVDS) within a time
frame of min. 22.5ms to max. 67.5ms after supply switch on.
In implementation, use 25ms, this makes it compatible with 37"HDSharp
(t=17.5ms is the supply switch-on delay taken into account)
Switch off the dimming backlight feature and
Restore dimming backlight feature and PWM outputand switch off RGB
blanking when valid, stable video, corresponding to the requested output is
delivered by the Viper AND the 1second delay has elapsed.
Switch Audio-Reset and sound enable low and demute
Figure 5-9 "Semi Stand-by" to "Active" flowchart
Semi Standby
Assert RGB video blanking
and audio mute
functions according needed use case.
clock.
Switch on LCD supply
(Viper: LCD-Power-on)
wait 250ms (min. = 200ms)
make sure PWM output is set to 100%
Switch on LCD backlight
Leave backlight on with PWM
at 100% for 1 second
Active
action holder: MIPS
action holder: St-by
autonomous action
Register PanelTiming of the Pacific3:
Timing is not important since the
LCD power signal is controlled by the
Viper, default values can be used.
G_16470_002.eps
301106