Read Sharp LC-20VM2E (serv.man6) FAQ online
29
LC-20VM2E
LC-121M2E
LC-150M2E
LC-150M2E
8. TROUBLE SHOOTING
No picture, No sound
Do F702 and F703 function?
Check T701's secondary load.
Check IC702, Q702, L701
and their peripheral parts.
and their peripheral parts.
Remove F702 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, Q704
and S4701?
primary side periphery, Q704
and S4701?
Replace F701 and F703.
YES
NO
YES
YES
YES
NO
NO
Check Q7751~Q7755,
T7751~Q7756 and their
peripheral parts.
T7751~Q7756 and their
peripheral parts.
Check IC1201, IC1206, IC2001
and their peripheral parts.
and their peripheral parts.
Replace the fluorecent lamp
with new one and check again.
with new one and check again.
Is primary oscillator waveform
of T7751~T7756 normal ?
of T7751~T7756 normal ?
Is the pin 11 of IC1201 in the
"H" state?
"H" state?
Does F7751 function?
Replace F7751.
Fluorecent lamp failure to light up.
YES
YES
YES
NO
NO
NO
NO
Are T701's secondary outputs,
+30V, +9V, +5.0V and -8V
normal?
+30V, +9V, +5.0V and -8V
normal?
Is T701's primary oscillator
waveform normal?
waveform normal?
Check IC406, IC402 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 of IC315
and 1, 7 of IC316
normal?
at pins 1 of IC315
and 1, 7 of IC316
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, IC451
and its peripheral
parts.
of IC406, IC451
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 IC315,
IC316 and its
peripheral parts.
IC316 and 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 IC853 normal?
(When inputting
except NTSC)
at pins 23 and 25
of IC853 normal?
(When inputting
except NTSC)
Check IC853,
Q852, Q854, Q857
and their peripheral
parts.
Q852, Q854, Q857
and their peripheral
parts.
Check IC402,
IC407 and their
peripheral parts.
IC407 and their
peripheral parts.
Check IC801 and
its peripheral parts.
its peripheral parts.
Are output voltages
at pin 6 of IC402 and
it of IC407 normal?
at pin 6 of IC402 and
it of IC407 normal?
Check Q802, Q803,
Q805, Q806 and
their peripheral parts.
Q805, Q806 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, IC451
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 Q407~Q410 and
their peripheral parts.
their peripheral parts.
Check peripheral
parts.
parts.
YES
YES
NO
NO
YES
Is output voltages
at pins 83 and 84
of IC7001 normal?
(When inputting
NTSC)
at pins 83 and 84
of IC7001 normal?
(When inputting
NTSC)
Check IC7001,
IC7002 and their
peripheral parts.
IC7002 and their
peripheral parts.
NO
YES
YES
YES
YES
YES
30
LC-20VM2E
LC-121M2E
LC-150M2E
LC-150M2E
Check in/output voltages of IC406.
YES
No colour appears
No colour (AV1, AV2 and Component)
Is output voltages
at pins 3 and 6 of
IC406, IC451
normal?
at pins 3 and 6 of
IC406, IC451
normal?
Check peripherals.
Are these voltages
as follows of IC801
normal?
pins 51 and 52
(input)
pins 41, 42 and
43 (output)
as follows of IC801
normal?
pins 51 and 52
(input)
pins 41, 42 and
43 (output)
Check IC801 and
its peripheral
parts.
its peripheral
parts.
No colour (AV1, AV2)
Is output voltages
at pin 6 of IC407
normal?
at pin 6 of IC407
normal?
Is input voltages
at pin 13 of
IC801 normal?
at pin 13 of
IC801 normal?
Is output voltages
at pins 5 and 6 of
IC801 normal?
at pins 5 and 6 of
IC801 normal?
Check in/output
voltages of IC406.
voltages of IC406.
Check IC407 and
its peripheral
parts.
its peripheral
parts.
Check peripherals.
No colour (Component)
YES
YES
YES
NO
NO
NO
NO
NO
Check IC801 and
its peripheral
parts.
its peripheral
parts.
No sound
Is 13V applied to the pin 9 of IC305?
Muted. Check
the FSMUT line.
the FSMUT line.
Is the pin 9 of
IC2001 in the
"L" state?
IC2001 in the
"L" state?
Check IC308,
IC316 and their
peripherals.
IC316 and their
peripherals.
Check speaker
unit and its
peripheral parts.
unit and its
peripheral parts.
Is the pin 10
of IC2001 in the
"L" state?
of IC2001 in the
"L" state?
Is output at pins
1 and 7 of
IC316 normal?
1 and 7 of
IC316 normal?
Is output at pins
10 and 17 of
IC305 normal?
10 and 17 of
IC305 normal?
Is output at pin
14 of IC305
normal?
14 of IC305
normal?
Is the pin 5
of IC2001 in the
"L" state?
of IC2001 in the
"L" state?
Check Q305,
J4001 and their
peripherals.
J4001 and their
peripherals.
YES
YES
YES
NO
Check IC305 their peripherals.
YES
YES
YES
YES
NO
NO
NO
YES
Check IC308,
IC304 and their
peripherals.
IC304 and their
peripherals.
Is output at pin
7 of IC304
normal?
7 of IC304
normal?
NO
Check Q308,
F703 and their
peripherals.
F703 and their
peripherals.
NO
YES
YES
YES
Check IC317 and
their peripherals.
their peripherals.
Is output at pins
1 and 7 of
IC317 normal?
1 and 7 of
IC317 normal?
NO
Check IC313,
IC314 and their
peripherals.
IC314 and their
peripherals.
Is output at pins
1 and 7 of
IC314 normal?
1 and 7 of
IC314 normal?
NO
YES
NO
NO
Check the
LSMUT line.
LSMUT line.
NO
Muted. Check
the RSMUT line.
the RSMUT line.
Does not output from the front
Does not output from the rear
Does not output from the headphones
Does not output from the line output
Is the pin 24
of IC2001 in the
"L" state?
of IC2001 in the
"L" state?
YES
31
LC-20VM2E
LC-121M2E
LC-150M2E
LC-150M2E
No colour appears
(N358)
(N358)
Is 3.5795 MHz
input into the
pin 10 of IC801?
input into the
pin 10 of IC801?
Check X801 and
its peripheral
parts.
its peripheral
parts.
No colour appears
(N443,PAL)
(N443,PAL)
YES
Is the C/Y signals at pins 13 and 15 of IC801 normal ?
Is the output at pins 10 and 11 of IC2802 normal ?
NO
Check X802 and
its peripheral
parts.
its peripheral
parts.
NO
Is 4.4336 MHz
input into the
pin 8 of IC801?
input into the
pin 8 of IC801?
YES
YES
Check
Peripheral
parts of IC853.
(When inputting
except NTSC)
Peripheral
parts of IC853.
(When inputting
except NTSC)
NO
Is the composite
signal which is
input into the pins
13 and 15 of
IC801 normal?
signal which is
input into the pins
13 and 15 of
IC801 normal?
Check Peripheral
parts of IC853.
parts of IC853.
NO
YES
Is 4 MHz input
into the pin 8 of
IC2802?
into the pin 8 of
IC2802?
Check X2850
and its peripheral
parts.
and its peripheral
parts.
NO
YES
Check Peripheral
parts of IC2802.
parts of IC2802.
NO
Is the output at pins 29 and 30 of IC2801 normal ?
Is the input at pins 51 and 52 of IC801 normal ?
Check Peripheral parts of IC801.
YES
Check Peripheral
parts of IC2801.
parts of IC2801.
YES
YES
NO
Check Peripheral
parts of IC406,
IC451.
parts of IC406,
IC451.
NO
No colour appears
(PAL-M)
(PAL-M)
Check X803 and
its peripheral
parts.
its peripheral
parts.
NO
Is 3.5756 MHz
input into the
pin 9 of IC801?
input into the
pin 9 of IC801?
Check IC7001,
IC7002, IC7100
and its peripheral
parts.
(When inputting
NTSC)
IC7002, IC7100
and its peripheral
parts.
(When inputting
NTSC)
YES
NO
No colour appears
(SECAM)
(SECAM)
Check X802 and
its peripheral
parts.
its peripheral
parts.
NO
Is 4.4336 MHz
input into the
pin 8 of IC801?
input into the
pin 8 of IC801?
YES
No picture in RGB mode.
Is input voltages
at pins 33~35 of
IC801 normal?
at pins 33~35 of
IC801 normal?
Is output voltages
at pins 41~43 of
IC801 normal?
at pins 41~43 of
IC801 normal?
Is input voltages
at pins 63, 110 of
IC1201 normal?
at pins 63, 110 of
IC1201 normal?
Check IC1201,
IC1203, IC801 and
its peripheral parts.
IC1203, IC801 and
its peripheral parts.
Check pins 33~35 of
IC801 and its
peripheral parts.
IC801 and its
peripheral parts.
Check IC1203, IC2001
and its peripheral parts.
and its peripheral parts.
YES
YES
YES
NO
NO
NO
Check pins 23~25, 32
of IC801 and its
peripheral parts.
of IC801 and its
peripheral parts.
