SONY KVEF34N90
Service Manual

KV-EF34N90
RM-913

6.

SELF-DIAGNOSTIC CIRCUIT

[+B overcurrent ªOCPº]

Occurs when an overcurrent on the +B(135) line is detected by Q604 (A board). If Q604 (A board) go to ON and the voltage to pin 18 of IC301 (A board) should go down when V.SYNC is more than seven verticals in a period, the unit will automatically turn off. Occurs when an overdrive on H drive line is detected by D526 (A board). Power supply will be shut down when detect it. Occurs when an absence of the vertical deflection pulse is detected by Q509 (A board) and IC001 (A board) shut down the power supply. Occurs when an overcurrent on V drive line is detected by Q507 (A board). Power supply will be shut down when detect this by IC001 (A board). If the RGB levels* do not balance or become low level within 5 seconds, this error will be detected by IC301 (A board). TV will stay on, but there will be no picture. * (Refers to the RGB levels of the AKB detection Ref pulse that detects IK.)

[Horizontal deflection overdrive] [Vertical deflection stopped] [Vertical deflection overcurrent] [White balance failure]

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