JVC PD-42WV74 Service Manual page 56

5.1.5 POINTS TO NOTE WHEN USING THE SELF-DIAGNOSIS FEATURE
In addition to circuit failures (abnormal operation), the following cases may also be iagnosed as "Abnormal" and displayed and counted
as "NG".
(1) Temporary defective transmissions across circuits due to pulse interruptions
(2) Misalignment in the on/off timing of power for I
Diagnosis may be impeded if a large number of items are displayed as "NG". As such, start self-diagnosis check only after 3 seconds
in the case of receivers and 5 seconds in the case of panels upon turning on the power. If recurrences are expected, ensure to clear
(reset) the failure history and record the new diagnosis reults.
5.1.6 DETAILS
Self-diagnosis is performed for the following items:
• PAGE 1
Item Display
LOW B LINE LOB
SHORT
PROTECTION
TIMER TIM
WITH / WITHOUT SYNC Are there synchronized signals?
SYNC SIGNALS
MEMORY MEM
AV SWITCH AVSW Same as above [IC1501]
VIDEO CHROMA VCD
AUDIO AIO
PROCESSING
3D Y/C YC
SEPARATION
RF TUNER TUN
GHOST GCR
REDUCTION
MULTI-SCREEN PP
PROCESSING
DIST IP
PROCESSING
HDMI HDMI
1-56 (No.YA029)
2
C bus (VCC) when turning on/off the main power.
Description of detection
Was Low B line short protector
activated?
No. of times short circuit protection
is triggered (9V/5V)
[Q1961, Q1962]
Did power supply frequency
fluctuated from:
50Hz → 60Hz
60Hz → 50Hz
Number of counts
[IC1701]
HD: Color difference synchronized
signals (Yes / No )
M: Main Synchronized signals
(Yes / No)
S: Sub-synchronized signals
(Yes / No)
[HD: IC1211 M,S: IC3001]
2
Is ACK returned during I C
transmission? [IC1703]
Same as above [IC301]
Same as above [IC6521]
Same as above [IC3001]
Same as above [IC1101]
Not used
2
Is ACK returned during I C
transmission? [IC1703]
Same as above [IC201]
Not used (Only display)
Diagnosis
Means of detection
signal (line)
9V/5V Detection starts 3 seconds upon
power on
Turns off power if NG is detected
within 200ms
AC Regularly detects power supply
frequency by AC pulse counts and
monitors frequency fluctuations other
than instances immediately after reset
SDA Checks whether there are
synchronized signal in video signal
SDA Monitors upon every I
and counts if ACK is not returned
SDA Same as above
SDA Same as above
SDA Same as above
SDA Same as above
SDA Same as above
----
SDA Monitors upon every I
and counts if ACK is not returned
SDA Same as above
----
Unit
Receiver
Receiver
Receiver
2
C transmission Receiver
Receiver
Display
Display
Receiver
Receiver
---- ----
2
C transmission Receiver
Receiver
---- ----