Sharp Aquous 4T-B70CJ1U, Service Manual, Page: 34 / 63

4T-B70CJ1 TROUBLE SHOOTING 4 - 32
Power unit operation check for 4T-B70CJ1U
YES
Power cord and harness in the unit
connected
Line filter unit? L4 ,L6,L6 ,L7 or RT1,RT2
is out of order?
YES
Are the power cord and harness in the
unit
NO
YES
YES
YES
If F1 normal
?
Does DB1 output 155V when AC
input 110V?
NO
Change a new full-wave rectifier diode to
check the output voltage.
Is the voltage of +13V applied to pin
11,14,15 of CN201?
Does the standby circuit normal?. (Q1, T1,
D201 , D4 , &the circuit around the U1 and
protection circuit ect. is checked)
YES
Does the U101 , Q101 ,T101,D103and the
circuit around IC U101? Check them.
NO
NO
NO
NO
Is VLED output 35V&39Vas for power
on/off switch when is on?
Does the U301,T301,Q301,Q302,
D306,D304and the circuit around IC U301?
Check them.
Is PFC output 320V as for power on/off
switch when is on?