KV-29FS12A - Sony TV Service Manual (repair manual). Page 6

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.

To clear the result display to “0”, press buttons on the Remote Commander sequentially when the diagnostic screen is displayed,
as shown below:

ENTER

Channel 8

To quit the entire self-diagnostic screen, turn off the power switch on the Remote Commander or the main unit.

MA BOARD

IC301

Y/CHROMA JUNGLE

A BOARD

IC502

V. OUT

MA BOARD

IC001

SYSTEM

MA BOARD

IC003

MEMORY

IK IN

FROM

CA BOARD

CN705 PIN 1 

   

36

HP/PROTECT

SDA

FROM

A BOARD

IC501 PIN 3

33

61

IO-SDAT

O-LED

43

REF

3

I-PROT

IO-BDAT

5

42

B-DAT

5

22

DISPLAY

Occurs when an overcurrent on the +B (135V) line is detected by pin 33 of IC301 (MA Board). If
the voltage of pin 33 of IC301 (MA Board) is less than 1V 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 pin 5 of IC001 (MA
Board). Power supply will shut down when waveform interval exceeds 2 seconds.

If the RGB levels* do not balance within 2 seconds after the power is turned on, this error will be
detected by IC301 (MA Board). TV will stay on, but there will be no picture.

*(Refers to the RGB levels of the AKB detection Ref pulse that detects 1K).