JVC AV-48P777/H Service Manual page 45

5.1.6 DETAILS
Self check is performed for the following items:
5.1.6.1 PAGE 1 OF SCREEN
Detection item Display
X-ray protection X-RAY
B1 over-current OCP
protection
Low bias line short LOB
protection
Timer (clock) TIM
Photo ditect PHOTO
DTVM and TVM Hostlink
communication
Fan lock FAN
5.1.6.2 PAGE 2 OF SCREEN
Detection item Display
US audio multiplexing MTS
decoder
Tone/volume control TONE
AV select switch AVSW
Component signal CompSW Same as above.
select switch
A-D converter for ADC
component signal
Tuner TUNER
A-D converter for audio Audio ADC Same as above.
Digital input DigitalIN
RGB/Def process RGB/DEF Confirmation of reply of ACK signal
Memory A-EEPROM Confirmation of reply of ACK signal
Detection content
Operation of X-ray protection circuit.
Q710 [MAIN PWB]
B1 over-current is detected.
Q971 [DEF & CONVERGENCE OUT PWB]
Operation of low B short protection circuit.
5V: Q961
9V: Q962 [MAIN PWB]
The power frequency is changed as
follows: 50Hz → 60Hz / 60Hz→50Hz.
IC701 [MAIN PWB]
Operation of the photo sensor.
Communication error between the
digital TV microcomputer and the TV
microcomputer is detected.
IC701 [MAIN PWB]
Not used.
Detection content
Confirmation of reply of ACK signal
which uses I2C communication.
Same as above.
Same as above.
Same as above.
Same as above.
Not used.
which uses I2C communication.
IC301 [MAIN PWB]
which uses I2C communication.
IC702 [MAIN PWB]
Diagnosis
Detection timing
signal (line)
X_RAY At about 3 seconds after the power is
turned on, the self-check function starts.
If NG is detected during 200ms, the
POWER LED is blinked.
OCP At about 3 seconds after the power is
turned on, the self-check function starts.
If NG is detected during 200ms, the power
is turned off automatically.
LOB_PRO At about 3 seconds after the power is
turned on, the self-check function starts.
If NG is detected during 400ms, the power
is turned off automatically.
AC_IN Detection starts 3 seconds after the
power is turned on. Periodically check the
power frequency by counting the AC
pulse and monitor whether or not the
frequency is changed.
DIGI_PHOT At about 3 seconds after the power is
turned on, the self-check function starts.
If NG is detected during 400ms,
irregularly is counted.
SDA Check communication errors by counting
the number of reset exception handling.
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Diagnosis
Detection timing
signal (line)
SDA If it checks whenever I2C communication
is performed and no reply of ACK signal
an error will be counted.
SDA Same as above.
SDA Same as above.
SDA Same as above.
SDA Same as above.
SDA Same as above.
SDA Same as above.
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SDA If it checks whenever I2C communication
is performed and no reply of ACK signal
an error will be counted.
SDA Same as above.
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(No.YA455)1-45