Chapter 4. Troubleshooting Table [1] Troubleshooting Table - Sharp LC-32LE40E Service Manual

CHAPTER 4.
TROUBLESHOOTING TABLE
[1] TROUBLESHOOTING TABLE
↓
Are the power cord and harness in the unit properly connected?
↓ YES
LINE_FILTER_UNIT:
Is F9901/F9902 normal?
↓YES
POWER_UNIT
Is B+_main(32")/B1+(42") output? (Set the main power SW to ON.)
↓YES
Is a voltage of +5.2V applied to pin (2,3) of connector
(CN9304(32")/CN907(42"))?
(Set the main power SW to ON.)
↓YES
Are 12 and 24V output as for the power on/off switch when it is on?
No sound output in all modes?
TERMINAL UNIT:
Is the audio signal output of IC U401 normal?
Is audio signal input to pin (15/20/21/22) of IC U602 (AMP)?
Is MUTE circuit [AMP_MUTE_LINE, POWERUP_LINE] normal?
Is the audio signal output of pin (1,2) (R) and pin (3,4) (L) of
CN601(AOUDIO-CONNECTOR) normal?
Check Speaker (right and left) and wire harness.
Power unit operation check.
The sound is not emitted from the speaker though the picture has come out.
↓
↓
↓YES
↓YES
↓YES
↓YES
NO
Connect the power cord and harness properly, and turn on the
power.
LINE_FILTER_UNIT:
Isn't NR9901,NR9902,IC9901,L9901,L9902(32")/L9903(42"),etc.
out of order? Moreover, whether the short-circuit with the
NO
circumference circuit is checked.
POWER_UNIT:
BD9901, FB9901, (FB9902, FB9906, D9101)(32")/(FB902,
FB9801, D9801)(42") etc. out of order? Moreover, whether the
short-circuit with the circumference circuit is checked.
NO Does the PFC circuit operate normally?
The circuit around the protection circuit etc. is checked.
NO
Does the switching circuit operate normally?
Check circuit around the primary side (IC9301, T9301,
D9303(32")/D9307(42"),etc.), the secondary side ((D9302,
L9301, ZD9316)(32")/(D9308, L9304, ZD9103(42"), etc.), and
the protection circuit.
Does the inverter circuit operate normally?
NO
Check circuit around the primary side (IC9103, T9101, Q9101,
etc.)(32")/(IC9101, T9101, Q9101, Q9102)(42"), the secondary
side ((IC9101, D9102, D9103)(32")/(IC9302, D9115,
D9116)(42"), etc.), and the protection circuit.
NO
Check IC U401 and its peripheral circuits.
NO
Check the line between IC U401 and IC U602.
NO Check the AMP_MUTE_LINE and POWERUP_LINE. (Q652,
Q653 etc.)
NO Check IC U602 and its peripheral circuits.
41
LC-32LE40E-LC-42LE40E