Sharp LC-19SH7E/RU, Service Manual, Page: 45 / 267

2008-03-14
LC-19SH7E/RU, LC-26SH7E/RU, LC-32SH7E/RU, LC-42SH7E/RU
45
CHAPTER 4.
TROUBLESHOOTING TABLE
[1] 19” TROUBLESHOOTING TABLE
Power unit operation check.
↓
LINE_FILTER_UNIT:
↓ YES
POWER_UNIT
↓ YES
↓ YES
↓ YES
Are the power cord and harness in the unit properly connected?
NO
Connect the power cord and harness properly, and turn on the
power.
Is F901 normal?
NO
LINE_FILTER_UNIT:
Isn't C908, RV901, L902, C900, C901, etc. out of order?
Moreover, whether the short-circuit with the circumference circuit
is checked.
Is BD901 (+320V) output?
* When power on/off switch is on
‧‧‧
About +400V
Does the circuit operate normally?
Check circuit around (FB901, Q906, ZD904, IC901 etc ).
NO
Is a voltage of +5.3V applied to pin (3,4) of connector (CN902)? Does the switching circuit operate normally?
Check circuit around the primary side (T901, ZD906, D901,
D903, Q903, D904, IC901, IC902, D905 etc.), the secondary
side (D905, L904, etc.), the DC_DET circuit (IC902, ZD903,
IC901, ZD902, etc.), and the protection circuit. NO
Is a voltage of +18V applied to pin (8,9) of connector (CN902)?
NO
Does the inverter circuit operate normally?
Check circuit around (Q801, ZD801, ZD802, Q805, Q806, IC801,
T801, L801, L802, etc.), and the protection circuit.