Advertisement
GB 30
5.
DVD703 /XX1
5.7.5
Play and 16/9 detection
Check DC voltage at S-Video-chroma output (pin 4) with a
6K8 ohm load and Scart connector (pin 8) and change the 0/
6/12 input (1010-8) using the following commands:
Command
Ref.#
Name
25a
VideoScartLo
25b
VideoScartMi
25c
VideoScartHi
5.7.6
Kill circuit
To check the functionality of the Kill circuitry,the audio
outputs has to be present by the following command:
Command
Ref.#
Name
21a
AudioPinkNois
eOn
Check the audio outputs at the audio cinch of the A/V board
: Pink Noise
Activate the Kill circuit by using the following command:
Ref.#
Command Name Remarks
19a
AudioMuteOn
Check the audio outputs at the audio cinch of the A/V board
: No waveform
Switch off the kill circuit by using the following command:
Ref.#
Command Name Remarks
19b
AudioMuteOff
Check the audio outputs at the audio cinch of the A/V board
: Pink Noise
5.8
Test instructions Display board
5.8.1
Introduction
These test instructions are written for all versions of the
display PCBAS.
The contents of the PCB can be split up into next blocks:
V filament
V filament
Buffer
I2C
Supply:
+5Vstby
+12V
-40V
Figure 5-41
Diagnostic software descriptions and troubleshooting
Remarks
Chroma output
Sends out 0V ±
<0.1V
0.5V
Sends out 6V ±
2.0V ± 10% with
10%
load
5.0V ± 10%
without load
Sends out 12V ±
<0.1V
10%
Remarks
Audio output
Audio Pinknoise
Pink Noise on 6
ON
channels
Audio Mute On
Audio Mute Off
Display
Key-matrix
µProcessor
P50
I/O
RC-Eye
5.8.2
Functionality description:
The essential component of the display PCB is the µP
(slave). This slave works on an 8MHz resonator and has a
reset circuit that is triggered by the +5Vstby. After the reset
pulse, the standby control line will release the reset of the
host µP. This host µP will then initialise the slave. In addition,
when going to stand-by, the slave will put the host µP in reset.
When the slave receives the right IR or key code to leave the
standby mode, the reset of the host µP will be released.
Other slave functions are:
•
Square signal generator to generate the filament voltage,
which is required for an AC FTD.
•
Generates the grid and segment scanning for the FTD.
•
Generates a scanning grid for the keys (separated from
display scanning).
•
Has inputs for RC (RC5 and RC6) and P50 (P50
controller is built in).
5.8.3
General
•
Oscilloscope measurements have been carried out using
a Philips PM3392A.
•
Impedance of measuring-equipment should be > 1MΩ.
•
To do correct measurements we recommend to use
supply 3122 427 22600.
CL 96532065_058.eps
130799
Advertisement
