Chapter 4. Troubleshooting Table; Troubleshooting Table - Sharp LC-19S7E-BK Service Manual

LC-19S7E-BK LC-26S7E-BK LC-32S7E-BK
CHAPTER 4.

TROUBLESHOOTING TABLE

[1] TROUBLESHOOTING TABLE（19"）
↓
Are the power cord and harness in the unit properly connected?
↓ YES
LINE_FILTER_UNIT:
Is F901 normal?
↓YES
POWER_UNIT
Is BD901 (+320V) output?
* When power on/off switch is on ‧‧‧ About +400V
Is a voltage of +5.3V applied to pin (3,4) of connector (CN902)?
Is a voltage of +18V applied to pin (8,9) of connector (CN902)?
Power unit operation check.
↓YES
↓YES
NO
Connect the power cord and harness properly, and turn on the
power.
LINE_FILTER_UNIT:
Isn't C908, RV901, L902, C900, C901, etc. out of order?
Moreover, whether the short-circuit with the circumference circuit
NO
is checked.
NO
Does the circuit operate normally?
Check circuit around (FB901, Q906, ZD904, IC901 etc ).
NO
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.
Does the inverter circuit operate normally?
NO
Check circuit around (Q801, ZD801, ZD802, Q805, Q806, IC801,
T801, L801, L802, etc.), and the protection circuit.
28