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KV-20S90 / 21SE43C
Self-Diagnostic Screen Display
For errors with symptoms such as “power sometimes shuts off” or “screen sometimes goes out” that cannot be confi rmed, it is possible to bring up
past occurrences of failure on the screen for confi rmation.
To Bring Up Screen Test
In standby mode, press buttons on the Remote Commander sequentially, in rapid succession, as shown below:
Display Channel 5
Sound Volume - Power ON
Self-Diagnostic Screen Display
Numeral “0” means that no fault was detected.
Numeral “1” means a fault was detected one time only.
SELF DIAGNOSTIC
2: 000
3: N/A
4: 000
5: 001
101: N/A
Handling of Self-Diagnostic Screen Display
Since the diagnostic results displayed on the screen are not automatically cleared, always check the self-diagnostic screen during repairs. When you
have completed the repairs, clear the result display to “0”.
Unless the result display is cleared to “0”, the self-diagnostic function will not be able to detect subsequent faults after completion of the repairs.
Clearing the Result Display
To clear the result display to “0”, press buttons on the Remote Commander sequentially when the diagnostic screen is displayed, as shown below:
Channel 8 ENTER
Quitting the Self-Diagnostic Screen
To quit the entire self-diagnostic screen, turn off the power switch on the Remote Commander or the main unit.
Self-Diagnostic Circuit
+B overcurrent (OCP)
Occurs when an overcurrent on the +B (115V) line is detected by pin 18 of IC301. If the voltage of pin 18 of IC301 is less than 1V when V.SYNC is more
than seven verticals in a period, the unit will automatically turn off.
Vertical Defl ection Stopped
Occurs when an absence of the vertical defl ection pulse is detected by pin 17 of IC001. Power supply will shut down when waveform interval
exceeds 2 seconds.
White Balance Failure
If the RGB levels* do not balance within 2 seconds after the power is turned on, this error will be detected by IC301. TV will stay on, but there
will be no picture.
*(Refers to the RGB levels of the AKB detection Ref pulse that detects 1K).
Note that this differs from entering the Service Mode (Sound Volume + ).
IC301
Y/CHROMA JUNGLE IC541
V. OUT
IC001
SYSTEM
IC003
MEMORY
IK IN
FROM
CRT
HP/PROTECT
SDA
FROM
IC521
PIN 7
18
IO-SDAT
O-LED
REF I-PROT
IO-BDAT BDA
DISPLAY
21
35
317
37 18
36 5