Sony KV-XA25M31 Service Manual page 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-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 as shown below when the diagnostic
screen is being displayed.
Channel [8] / 0
[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
FROM
CRT
FROM
[+B] Q604 C6
[V] Q509/507
[+B overcurrent ªOCPº]
[Vertical deflection stopped]
[Vertical deflection overcurrent]
[White balance failure]
IC301
Y/CHROMA JUNGLE
21 IK-IN
MP/
18
PROTECT
SDA 35
Occurs when an overcurrent on the +B(135) line is detected by Q604. If Q604 go to ON
and the voltage to pin 18 of IC301 should go down when V.SYNC is more than seven
verticals in a period, the unit will automatically turn off.
Occurs when an absence of the vertical deflection pulse is detected by Q509 and IC001
shut down the power supply.
Occurs when an overcurrent on V drive line is detected by Q507. Power supply will be
shut down when detect this by IC001.
If the RGB levels* do not balance or become low level within 5 seconds, 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 IK.)
– 7 –
KV-XA25M61/XA29M31/XA25M90/XA25M80/XA25M50
KV-XA25M87/XA25M84/XA25M86
IC001
SYSTEM
45
IO-8DAT
O-LED 51
46 IO-SDAT
RM-954
RM-953
IC003
MEMORY
5
B-DAT