Sony TRINITRON KV-21CT1B Servicehandbuch Seite 7

5. 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-diagnosis 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 subsequent as shown below when the
self-diagnostic screen is being displayed.
8 / -
[Quitting Self-diagnostic screen]
To quit the entire self-diagnostic screen, turn off the power switch on the remote commander or the main unit.
6. SELF-DIAGNOSTIC CIRCUIT
A BOARD
Y/CHROMA JUNGLE
FROM
C BOARD
84 IK
IC751 PIN 5
A BOARD
32 EHTO
FROM
Q804
COLLECTOR
[+B overcurrent $OCP%]
[V-PROTECT]
[IK $AKB%]
[HV PROTECT]
* (Refers to the RGB levels of the AKB detection Ref pulse that detects IK.)
A BOARD
IC001 IC804
V.OUT
F.B-PLS 3
Occurs when an overcurrent on the +B(135V) line is detected by pin 32 of IC001 (A board).
If the voltage of pin 32 of IC001 (A board) is more than 4V, the unit will automatically go to
standby.
Occurs when an absence of the vertical deflection pulse is detected by pin 13 of IC001
(A board).
If the RGB levels* do not balance within 15 sec after the power is turned on, this error will be
detected by IC001 (A board). TV will stay on, but there will be 5 times LED blinking.
Occurs when IC001 internal HV protect detects an abnormal H-Pulse (frequency) due to
improper power supply to IC001. TV cuts off high voltage power of anode CRT. No picture will
be detected. eg: IC602, IC604 go faulty.
KV-21CT1B/21CT1U/21CT1E/21CT1K
A BOARD
IC001
SYSTEM
SDA1
99
13
V.GUARD
RED LED 122
– 7 –
RM-W100
A BOARD
IC003
MEMORY
5 SDA
DISPLAY