JVC AV-56P776 Service Manual page 54

5.1.6 DETAILS
SELF CHECK is performed for the following items:
Check Item Indication
X-ray protection XRAY
B1 over-current OCP
protection
Low B short protection LOB
CRT neck protection
Timer (clock) TIM
Presence or absence SYNC
of synchronized
signal
Main memory MEM
AV switch AVSW
Video process VCD
Audio process AIO
3D YC separation YC
RF tuner TUN
Multi screen PP
DIST process IP
Digital input process HDMI
Split protection SPRT
5.1.7 DISPLAY METHOD WHEN RASTER IS NOT AVAILABLE
The self check results are shown on the following LED display.
Method of indication when the raster is not displayed.
Each failure is shown by turning LED on and off at the specified
intervals.
• For B1 over-current protection, CRT neck protection and Low
B short protection, the power of the TV is turned off, if NG is
detected. Immediately after the power is turned off, POWER
LED will be turning on and off. When the power is turned off,
you cannot turn the power on again until the AC plug is taken
out and put in again.
Details of detection
Operation of X-ray protection circuit.
Q1853 [MAIN PWB]
B1 over-current is detected.
Q971 [DEF & CONVERGENCE OUT PWB]
Operation of low B short protection circuit.
5V: Q1961
9V: Q1962 [MAIN PWB]
Operation of CRT neck protection circuit.
Q402 [DEF & CONVERGENCE OUT PWB]
The power frequency is changed as follows:
→ →
50Hz 60Hz / 60Hz 50Hz
IC1701 [MAIN PWB]
Presence of synchronized signal.
HD: Component input / M: NTSC main / S: NTSC sub
IC1301 [MAIN PWB]
2
ACK is returned when I C traffic is carried out.
IC1803 (memory) [MAIN PWB]
Ditto
IC1501 and IC1801 [MAIN PWB]
Ditto
IC1301 [MAIN PWB]
Ditto
IC1140 [MAIN PWB]
Ditto
IC3101 [DIGITAL SIGNAL PWB]
Ditto
TU1101 [MAIN PWB]
Not used
2
ACK is returned when I C traffic is carried out.
IC3001 [DIGITAL SIGNAL PWB]
Ditto
Not used
Method of detection
At about 3 seconds after the power is turned on, the self-
check function starts.
If NG is detected for 200ms, POWER LED is turned on and off.
At about 3 seconds after the power is turned on, the self-check
function starts.
If NG is detected for 200ms, the power is turned off automatically.
At about 3 seconds after the power is turned on, the self-check
function starts.
If NG is detected for 200ms, the power is turned off automatically.
At about 3 seconds after the power is turned on, the self-check
function starts.
If NG is detected for 1.5s, the power is turned off automatically.
Periodically check the power frequency by counting the AC
pulse and monitor whether or not the frequency is changed
except for the time immediately after resetting.
When entering the self-check mode, "OK" is shown.
While running the mode with picture signal, if the
synchronized signal is disappeared, "NG" is shown.
The state is monitored every time when I
Then the state is counted as a failure if ACK is not returned.
Ditto
Ditto
Ditto
Ditto
Ditto
---
The state is monitored every time when I
Then the state is counted as a failure if ACK is not returned.
Ditto
---
Item
Turning on and off at 0.1-second intervals
X-ray protection
B1 over-current protection Turning on and off at 1-second intervals
Low B short protection Turning on and off at 2-second intervals
CRT neck protection Turning on and off at 3-second intervals
2
C traffic is carried out.
2
C traffic is carried out.
POWER LED ON / OFF intervals
(No.YA318)1-53