GB 305.DVD612 /XX1Diagnostic software descriptions and troubleshooting
5.7Test Instruction Audio/Video Board5.7.3 Audio DAC and amplifier
These test instructions can be used for all versions of the A/Ensure that the Audio mute signal is OFF
V board which has the following outputs:To check the DAC and buffer amplifier,send the following
Audio L/Rcommands:
5.1 Audio outputCommand
Subwoofer outputRef.#NameRemarksAudio output
Optical / Coaxial digital output21aAudioSineOn Audio Sine Sine,1Khz on
CVBSsignal ONstereo
Y/G_vid,U/B_vid,V/R_vid output
----Press stop Audio Sine No waveform
S-videobuttonsignal OFF
Scart output
20aAudioPinkNoisAudio Pink Noise on
eOnPinknoise ON6 channels
5.7.1 General
20bAudioPinkNoisAudio No waveform
All the waveforms measurement carried out in these test eOffPinknoise OFF
instruction will be base on the testpoint indicated in the A/The audio signal ( sine or pink noise ) will also be present on
V board schematic diagram in the Service manual.
Impedance of the measuring-equipment should be > the digital output ( SPDIF ).This can be checked by
1M&connecting digital signal to an amplifier with digital input.
Check the I2S and audio signal at the following testpoints:
Most of the tests can be done using either the Diagnostic
software ? Player script? which can be found in the NameTestpoint
chapter ?Diagnostic Software description and LRCLKTP8
troubleshooting? or the Menu interface using the Service
SCLKTP9
PC with a terminal emulation program ( e.g. Window PCM_CLKP10
Hyperterminal ) where it is possible to control the
execution of the Diagnostic NucleiPCM_OUT0TP7
Setup for the measurement will be done in set level with PCM_OUT1TP27
all modules connected as shown in the Wiring Block PCM_OUT2TP28
diagram.
SPDIFTP11
Front L/R out-Audio cinchTP13
5.7.2 General start-up measurement
H/P L/R outTP20
Analog out -Audio cinchTP25
Supply check:
Before starting the measurement,ensure that all power
supply are connected to the A/V board.All waveforms can be refer to the waveform diagram in the
chapter ?Diagnostic software description and
Pin nbrSupplytroubleshooting?.
1010-9-5V ( -Vcc )
1010-10+5V5.7.4 Video output and buffer amplifier
1010-11+5V
Check DC output-level at all video cinch output : 1.0V DC ?
The supply currents can be measured using a Tektronics 10%
AM503B current probe or equivalent.Generate a color bar using the following software
commands:
SupplyPower consumption ( AVG )
+5VA+5V ? 3% I = 200mARef.# Command Name Remarks
+5Vvid+5V ? 3% I = 200mA23aVideoColDencOn Colour DENC ON
-5V-5V ? 3% I = 200mA61aVideoColOutRGB RGB Colourbar
61bVideoColOutYUV YUV Colourbar
Clock Check23bVideoColDencOff Colourbar DENC OFF
Ensure the present of the clock to the DAC
Clock Name Testpoint FrequencyCheck the video outputs at the following testpoints:
PCM_CLKTP1011.2896MHz ? 0.02% toleranceNameTestpoint
B_VIDTP1
Audio mute check
Measure the Audio mute voltage input at pin 12 of connector G_VIDTP2
R_VIDTP3
1010
StatusValueCVBS outTP14
S-Video-C out TP15
AudioMuteOn 4.7V ? 10%
AudioMuteOff -8V ? 10%S-Video-Y out TP16
Y outTP17
To toggle between ON and OFF,use the following U outTP18
commands:V outTP19
Command
All waveforms can be refer to the waveform diagram in the Ref.#NameRemarks
chapter ?Diagnostic Software description and
troubleshooting?.19aAudioMuteOn Audio Mute On
19bAudioMuteOff Audio Mute Off |
ACEC
PHILIPS
