Read Sharp LC-121M2E (serv.man3) Service Manual online
23
LC-121M2E
LC-150M2E
LC-150M2E
LC-121M2E
LC-150M2E
LC-150M2E
7. TROUBLE SHOOTING
No picture, No sound
Do F701 and F703 function?
Check T701's secondary load.
Check IC702, Q702, L701
and their peripheral parts.
and their peripheral parts.
Remove F701 and F703, and
check the load side.
Is there short-circuiting?
check the load side.
Is there short-circuiting?
Is there short-circuiting of T701
primary side periphery, Q701
and S701?
primary side periphery, Q701
and S701?
Replace F701 and F703.
YES
NO
YES
YES
YES
NO
NO
Check Q751, Q752, Q753,
Q754, T751, T752 and their
peripheral parts.
Q754, T751, T752 and their
peripheral parts.
Check Q703 and its peripheral
parts.
parts.
Replace the fluorecent lamp
with new one and check again.
with new one and check again.
Is primary oscillator waveform
of T751 and T752 normal ?
of T751 and T752 normal ?
Does Q703 function?
Does output voltage +9V
appear?
Does output voltage +9V
appear?
Does F702 function?
Fluorecent lamp failure to light up.
YES
YES
YES
NO
NO
NO
Are T701's secondary outputs,
+30V, +23V, +9V, +5.1V and
-5.5V normal?
+30V, +23V, +9V, +5.1V and
-5.5V normal?
Is T701's primary oscillator
waveform normal?
waveform normal?
Check IC406, IC403 and their peripheral parts.
No picture (AV1, AV2 and Component)
Is output voltages
at pins 3,5 and 6 of
IC406 normal?
at pins 3,5 and 6 of
IC406 normal?
Is input voltages at
pins 51,52 and 53
of IC801 normal?
pins 51,52 and 53
of IC801 normal?
Is output voltages at
pins 41,42 and 43
of IC801 normal?
pins 41,42 and 43
of IC801 normal?
Is output voltages
at pins 1,7 and 8 of
IC803 normal?
at pins 1,7 and 8 of
IC803 normal?
No picture (AV1, AV2)
Replace LCD module with new one and check again.
Replace cables with new one and check again.
No picture
Check the in/output
of IC406 and its
peripheral parts.
of IC406 and its
peripheral parts.
No picture (AV1/AV2)
No picture (Component)
Is signal input into the pin
13 of IC2001?
13 of IC2001?
Check IC406 and
its peripheral parts.
its peripheral parts.
Check IC801 and
its peripheral parts.
its peripheral parts.
Check IC803 and
its peripheral parts.
its peripheral parts.
Is in/output voltages of IC1001 normal?
Is in/output voltages of IC1201 normal?
Are voltages and waveform of the LCD module connecting connector normal?
Aren't cables break down?
Is in/output voltages
of IC401 normal?
of IC401 normal?
Check IC401 and
its peripheral parts.
its peripheral parts.
Is output voltage at pin 18 of IC801 normal?
Is input voltages at pins 33 and 15 of
IC801 normal?
IC801 normal?
Check IC401 and
its peripheral parts.
its peripheral parts.
Is output voltages
at pins 23 and 25
of IC851 normal?
at pins 23 and 25
of IC851 normal?
Check IC851,
Q852, Q854, Q857
and their peripheral
parts.
Q852, Q854, Q857
and their peripheral
parts.
Check IC403,
IC405 and their
peripheral parts.
IC405 and their
peripheral parts.
Check IC801 and
its peripheral parts.
its peripheral parts.
Are output voltages
at pin 7 of IC403 and
it of IC405 normal?
at pin 7 of IC403 and
it of IC405 normal?
Check Q801, Q802
and their peripheral
parts.
and their peripheral
parts.
Is input voltages
at pins 13 and 15
of IC801 normal?
at pins 13 and 15
of IC801 normal?
Is output voltages
at pins 4,5 and 6
of IC801 normal?
at pins 4,5 and 6
of IC801 normal?
Check in/output voltages of IC406
and its peripheral parts.
and its peripheral parts.
NO
No picture apears (AV1)
YES
YES
YES
YES
YES
YES
YES
YES
NO
NO
NO
NO
NO
NO
NO
NO
NO
NO
Check Q401~Q406 and
their peripheral parts.
their peripheral parts.
Check peripheral
parts.
parts.
YES
YES
NO
NO
YES
YES
YES
YES
YES
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