Sharp LC-26SH7E/RU Service Manual page 84

LC-19SH7E/RU, LC-26SH7E/RU, LC-32SH7E/RU, LC-42SH7E/RU
42" TROUBLESHOOTING TABLE
↓
Are the power cord and harness in the unit properly connected?
↓ YES
LINE_FILTER_UNIT:
Is F901/F902 normal?
↓YES
POWER_UNIT
Is BD901 (+320V) output? (Set the main power SW to OFF.)
* When power on/off switch is on ‧‧‧ About +400V
↓YES
Is a voltage of +5V applied to pin (12,13) of connector (CN902)?
(Set the main power SW to OFF.)
↓YES
Are +24V output as for the power on/off switch when it is on?
↓YES
Similarly, is +12V output as for the power on/off switch when it is
on?
Power unit operation check.
NO
Connect the power cord and harness properly, and turn on the
power.
LINE_FILTER_UNIT:
Isn't
C908,RV902,L901,C909,C901,C902,C904,L092,FB922,FB923,
NO
RV904 etc. out of order? Moreover, whether the short-circuit with
the circumference circuit is checked.
POWER_UNIT:
BD901, C935, L903, etc. out of order?
Moreover, whether the short-circuit with the circumference circuit
is checked.
NO
Does the PFC circuit operate normally?
(IC909,Q922,D933,IC901,Q917,Q923 and etc. And, the circuit
around the protection circuit etc. is checked.)
NO
Does the switching circuit operate normally?
Check circuit around the primary side (T904, IC903, Q924,
ZD910, ZD911, ZD912, ZD913, etc.), the secondary side (D927,
L907, etc.), the AC_DET circuit (IC911, IC913, etc.), and the
protection circuit.
Does the inverter circuit operate normally?
NO
Check circuit around the primary side
(T905,Q919,Q920,IC902,D936,D937, etc.), the secondary side
(D901, D902,C951,C952,L906,L908,IC914, etc.), the STANDBY
circuit (Q915, etc.), and the protection circuit.
Check +12V circuit of D928, L909, etc.
NO
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