Sony KV25FS150 no startup.

[SEAWOLF]

I am presently servicing a Sony KV25FS150 which does not power on when the
power switch is pressed.The standby light is not lighted when the tv is plugged
to the AC supply or blinking.I know when problems arise in Sony televisions the
standby light blinks.There is DC on the filter capacitor,the regulator and also the flyback transformer.

[R_J]

Re: Sony KV25FS150 no startup.

Do you have the schematic? kv29FS150 should be the same.
Do you have 135 volts on the horzontal output transistor (Q511)
Flyback tranformer is the high voltage transformer (T503)
or do you mean the power transformer (T602)
The SWITCHING regulator ic in the power supply is STR-W6753 It should have 150 volts on pin (1) and 11 volts on pin (4) [measured to HOT ground]
Check the resistance of R610 & R619 .33 & .22 ohm

[SEAWOLF]

Re: Sony KV25FS150 no startup.

Do you have the schematic? kv29FS150 should be the same.
Do you have 135 volts on the horzontal output transistor (Q511)
Flyback tranformer is the high voltage transformer (T503)
or do you mean the power transformer (T602)
The SWITCHING regulator ic in the power supply is STR-W6753 It should have 150 volts on pin (1) and 11 volts on pin (4) [measured to HOT ground]
Check the resistance of R610 & R619 .33 & .22 ohm

I have a schematic and I have 43.3 volts on the horizontal output transistor and
162 volts on pin(1) and 10.4 volts on pin (4) for STR-W6735.These voltages are
taken when the television is in standby,because it will not switch on when the
power switch is pressed.The standby LED is not lighted when the television is in
standby.

[R_J]

Re: Sony KV25FS150 no startup.

Check D517 and D518 I replaced lots of those diodes in the past, usually one shorts, they are near the horz. putput transistor, you should have 143v on that transistor and about 70v on the driver Q506