Sony Trinitron KV-32FV27 Service Manual page 7

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
Self-diagnostic Screen Display
SELF DIAGNOSIS
2: +B OCP N/A
3: +B OVP N/A
4: VSTOP 0
Numeral "0" means that no fault was detected.
5: AKB 1 Numeral "1" means a fault was detected one time only.
101: WDT 24
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
A BOARD
IC355
Y/CHROMA JUNGLE
FROM
C BOARD
21 IK IN
IC1701 PIN 6
A BOARD
18
HP/PROTECT
FROM
IC501
PIN 1
+B overcurrent (OCP) Occurs when an overcurrent on the +B (135V) line is detected by pin 18 of IC355 (A Board). If the voltage of pin 18 of
IC355 (A Board) is less than 1V when V.SYNC is more than seven verticals in a period, the unit will automatically turn off.
+B overvoltage (OVP) Occurs when the feedback circuit from +B opens IC643 or T603 or any other associated feedback components.
V-STOP Occurs when an absence of the vertical defl ection pulse is detected by pin 15 of IC355 (A Board). Power supply will
shut down when waveform interval exceeds 2 seconds.
IK (AKB) If the RGB levels* do not balance within 2 seconds after the power is turned on, this error will be detected by IC355
(A Board). TV will stay on, but there will be no picture.
NOTE:
Watch Dog Timer Indicates how many times the Watch Dog Timer functions have been activated. Whenever micro is reset by the Watch
Dog Timer, this number is incremented. Maximum number is 255.
* Refers to the RGB levels of the AKB detection Ref pulse that detects 1K.
Sound Volume -
Power ON
Note that this differes from entering the Service Mode (Sound volume + ).
A BOARD
IC561
V. OUT
VM 15
3 REF
SDA 35
A BOARD
IC001
SYSTEM
IO-BDATN
26
O-TIMELED
59
27
IO-SDAT
— 7 —
KV-32FV27 / 36FS13 / 36FS17 / 36FV27/ 38FS17
A BOARD
IC1002
MEMORY
5
BDA
DISPLAY