Hello, please help me i have same problem on my Sharp Aquos 60LC635E No 5V power, tv dead . Blown R7900 and short D7950 . I changed it, than blown R7900 again . D7950 ok. I change IC7903 and cap on 5 leg 50V 47u and R7900 never blown again but 5V not( I do not know what to do . On big two cap 315V, on 5 leg IC7903 9V this very low for start A6069H . Datasheet say min 13V.
Please Help me. board power supply dps-162KP B RUNTKA932WJQZ
The voltage isn't high enough, just like you said here, the question is why, I can't figure it out but one of the pros knows I bet.
9.1 Startup Operation
Figure 9-1 shows the circuit around IC. Figure 9-2
shows the start up operation.
The IC incorporates the startup circuit. The circuit is
connected to D/ST pin. When D/ST pin voltage reaches
to Startup Circuit Operation Voltage VST(ON) = 38 V, the
startup circuit starts operation.
During the startup process, the constant current,
ISTARTUP = − 2.5 mA, charges C2 at VCC pin. When
VCC pin voltage increases to VCC(ON) = 15.3 V, the
control circuit starts operation
I assume no responsibility for any stupid suggestions I might post.
9.1 Startup Operation
Figure 9-1 shows the circuit around IC. Figure 9-2
shows the start up operation.
The IC incorporates the startup circuit. The circuit is
connected to D/ST pin. When D/ST pin voltage reaches
to Startup Circuit Operation Voltage VST(ON) = 38 V, the
startup circuit starts operation.
During the startup process, the constant current,
ISTARTUP = − 2.5 mA, charges C2 at VCC pin. When
VCC pin voltage increases to VCC(ON) = 15.3 V, the
control circuit starts operation
What is the voltage on pin 4 of ic7903, this is the FB (feedback) voltage.
Is R7907 ok?
IC7801 will not effect ic7903. IC7801 is the pfc driver ic. and is not active in standby
What is the voltage on pin 4 of ic7903, this is the FB (feedback) voltage.
Is R7907 ok?
IC7801 will not effect ic7903. IC7801 is the pfc driver ic. and is not active in standby
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