Sharp 4T-B70CJ1U Service Manual page 34

Are the power cord and harness in the
unit
?
If F1 normal
Does DB1 output 155V when AC
input 110V?
Is the voltage of +13V applied to pin
11,14,15 of CN201?
Is PFC output 320V as for power on/off
switch when is on?
Is VLED output 35V&39Vas for power
on/off switch when is on?
Power unit operation check for 4T-B70CJ1U
YES
YES
YES
YES
NO
YES
NO
YES
NO
4T-B70CJ1 TROUBLE SHOOTING
NO Power cord and harness in the unit
connected
NO
Line filter unit? L4 ,L6,L6 ,L7 or RT1,RT2
is out of order?
NO Change a new full-wave rectifier diode to
check the output voltage.
Does the standby circuit normal?. (Q1, T1,
D201 , D4 , &the circuit around the U1 and
protection circuit ect. is checked)
Does the U101 , Q101 ,T101,D103and the
circuit around IC U101? Check them.
Does the U301,T301,Q301,Q302,
D306,D304and the circuit around IC U301?
Check them.
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