Read Sharp LL-T2010W (serv.man15) Service Manual online
LL-T2010W
TROUBLE SHOOTING
4 – 1
CHAPTER 4. TROUBLE SHOOTING
Check whether the following cables are connected correctly.
In addition, check whether the PCs video mode is properly set to the signal timing witch meets this machine.
In addition, check whether the PCs video mode is properly set to the signal timing witch meets this machine.
*
Attached cables
• Dedicated AC adapter
• Dedicated signal cable (RGB cable, DVI cable)
(No)
(Yes)
1
When the power button is pressed, does
LED light up?
LED light up?
Execute
(No)
(Yes)
1
1
When the RGB cable is disconnected,
does LED change from Green to Orange?
does LED change from Green to Orange?
Execute
(No)
(Yes)
2
When the RGB cable is connected, does
LED keep Green? (No change from
Green to Orange)
LED keep Green? (No change from
Green to Orange)
Execute
(No)
(Yes)
3
Does B/L light up?
Execute
(No)
(Yes)
4
Does the display work normally in each
video mode?
video mode?
No abnormality
Execute
(No)
(Yes)
2
Is 5V (main PWB D22 cathode) supplied?
Execute
(No)
(Yes)
2
Does Q9 (1PIN)-R185 output? (3V)
Execute
(No)
(Yes)
Does FB7-CN5 (2PIN) output? (1.9V)
Check connection of the SW cable and
the SW PWB.
the SW PWB.
Check 09 and its peripheral circuits.
2
(No)
(Yes)
Is the input signal port connected with the
analog signal cable?
analog signal cable?
Press INPUT key to switch to the
proper input signal port.
proper input signal port.
Check the DC+5V power line and the
IC19 peripheral circuits.
IC19 peripheral circuits.
Check the DC+12V power line, F1, F2,
D1, D2 of the DC jack PWB, and their
peripheral circuits.
D1, D2 of the DC jack PWB, and their
peripheral circuits.
Check the exclusive-use AC adapter.
(No)
(Yes)
Is DC+12V supplied from the exclusive-
use AC adapter?
use AC adapter?
(No)
Is CN8-3PIN at DC+12V?
(Yes)
(No)
Is D21 cathode at DC+5V?
The display does not work. (Analog RGB)
LL-T2010W
TROUBLE SHOOTING
4 – 2
(No)
(Yes)
Is D23 cathode at DC+3.3V?
Check the DC+3.3V power line and the
IC21 peripheral circuits.
IC21 peripheral circuits.
Check the DC+2.5V power line and the
IC22 peripheral circuits.
IC22 peripheral circuits.
Check the POWER_CTL signal and
IC18 peripheral circuits.
IC18 peripheral circuits.
Check the RESET circuit in the
peripheral of IC16.
peripheral of IC16.
Check the peripheral circuits of IC24
X1.
X1.
Check the clock circuit in the peripheral
of IC6 X2.
of IC6 X2.
Check the analog signal cable and CN1
(CN2).
(CN2).
Check the peripheral circuits of IC3 and
IC4.
IC4.
Execute . Microcomputer circuit
check/GM5060
check/GM5060
Check the peripheral circuits of IC2.
Check the peripheral circuits of Q7.
Check the MAINPW signal and wiring
between CN5 the main SW on the SW
PWB.
between CN5 the main SW on the SW
PWB.
(No)
(Yes)
Is D25 cathode at DC+2.5V?
(No)
(Yes)
Is the voltage across the fuse F4
DC+12.0V?
DC+12.0V?
(No)
(Yes)
Is the positive side (no connection of part)
of C145 at H level (DC+5V)?
of C145 at H level (DC+5V)?
(No)
(Yes)
Is the FB15 level changed by turning
on/off the POWER SW?
on/off the POWER SW?
(No)
(Yes)
Is the output level of Q7 (connected with
R35) at L level (DC+0V)?
R35) at L level (DC+0V)?
(No)
(Yes)
Is IC15-21PIN oscillating?
(No)
(Yes)
Is X3's PIN on C111 side oscillating?
(No)
(Yes)
Are the signal waveforms of R35 and R37
(R25, R28) normal?
(R25, R28) normal?
(No)
(Yes)
Is the signal waveform of R45 (R34)
normal?
normal?
(No)
(Yes)
Are the signal waveforms of R74 and R76
normal?
normal?
When R94 and R95 are disconnected,
are the waveforms on IC8 side normal?
are the waveforms on IC8 side normal?
Check the DCLK DEN line.
(No)
Replace IC8.
(No)
Are the signal waveforms of R94 and R95
normal?
(Connect the cable of CN10 and CN11.)
normal?
(Connect the cable of CN10 and CN11.)
(No)
(Yes)
(Yes)
(Yes)
Are the signal waveforms of test pins
TP22 and TP23 normal? (The cable of
CN10 and CN11 at the back can be
disconnected.)
TP22 and TP23 normal? (The cable of
CN10 and CN11 at the back can be
disconnected.)
Continued from
2
5
LL-T2010W
TROUBLE SHOOTING
4 – 3
(No)
(Yes)
Are the waveforms of RN31~RN35
normal?
normal?
Is the positive side (no connection of
part) of C163 at DC+3.3V?
part) of C163 at DC+3.3V?
Is R213 at H level (DC+3.3V)?
When the LCD module is disconnected,
are the waveforms of RN31~RN35
normal?
are the waveforms of RN31~RN35
normal?
Replace the LCD module.
Check the DC+12V power line and fuse
F2.
F2.
Check the main PWB in the peripheral
of Q11, Q12, D20, and CN7, and check
the DC jack PWB.
of Q11, Q12, D20, and CN7, and check
the DC jack PWB.
Replace the inverter PWB unit.
Check the main PWB in the peripheral
of IC14, and check the DC jack PWB.
of IC14, and check the DC jack PWB.
Check the peripheral circuits of R203
and IC21.
and IC21.
Check the peripheral circuits of IC18.
(No)
(Yes)
Is the positive side of C164 at DC+12V?
(No)
(Yes)
Is CN11-20PIN at DC+3.3V?
Replace the LCD module.
(No)
(Yes)
Are 1PIN and 2PIN of CN3 on the DC jack
PWB at DC+12V?
PWB at DC+12V?
(No)
(Yes)
Is Cn7-5PIN at DC+5V?
(No)
(Yes)
Are test pins LD3 and LD4 at DC+2.5V or
less?
less?
(No)
(Yes)
Is 1PIN of CN2~CN7 on the inverter PWB
about 750Vrms? (Be careful of electric
shock. For voltage measurement, use a
high-voltage probe of 100:1 or more.)
about 750Vrms? (Be careful of electric
shock. For voltage measurement, use a
high-voltage probe of 100:1 or more.)
Check the lamp in the LCD module.
(Yes)
(Yes)
(No)
(No)
(No)
Check the peripheral circuits of FB16
and IC21.
and IC21.
Check Q10 and POWER_LINE signal.
Check the peripheral circuits of IC17.
(Yes)
(Yes)
(Yes)
Continued from
2
3
Check the DC+5V power line and the
IC19 peripheral circuits.
IC19 peripheral circuits.
Check the DC+3.3V power line and the
IC21 peripheral circuits.
IC21 peripheral circuits.
(No)
(Yes)
Is D21 cathode at DC+5V?
(No)
Is D23 cathode at DC+3.3V?
4
LL-T2010W
TROUBLE SHOOTING
4 – 4
(No)
Is D25 cathode at DC+2.5V?
Check the DC+2.5V power line and the
IC22 peripheral circuits.
IC22 peripheral circuits.
(Yes)
(Yes)
Does the whole display remain black?
Is the voltage across the fuse F3
DC+12.0V?
DC+12.0V?
(No)
Check the POWER_CTRL2 signal and
the Q4 peripheral circuits.
the Q4 peripheral circuits.
(No)
(Yes)
(Yes)
Is the display size abnormal?
Is the setup item of MODE SELECT in
the adjustment properly set?
the adjustment properly set?
Check X1, X3, IC15, the peripheral
circuits, and the software.
circuits, and the software.
(No)
Adjust properly according to the display
adjustment procedure.
adjustment procedure.
(No)
(Yes)
When the whole black display is shown
from the signal source, is there any flicker
of colors?
from the signal source, is there any flicker
of colors?
Check IC10, IC11, IC12, and the
peripheral circuits.
peripheral circuits.
(No)
(Yes)
(Yes)
Is there any deflection or flicker on the
LCD display?
LCD display?
Is the setup item of MODE SELECT in
the adjustment properly set?
the adjustment properly set?
Check IC2, IC3, IC4, and the peripheral
circuits.
circuits.
(No)
Adjust properly according to the display
adjustment procedure.
adjustment procedure.
(No)
(Yes)
(Yes)
(Yes)
Is there any abnormality in colors of the
LCD display?
LCD display?
Are the setup items of GAIN CONTROL
and WHITE BALANCE properly set?
and WHITE BALANCE properly set?
(No)
Adjust properly according to the display
adjustment procedure.
adjustment procedure.
(No)
(Yes)
Is the analog color signal output
normal? (Pins on C7, C11, C15, C18
side)
normal? (Pins on C7, C11, C15, C18
side)
(No)
Check the IC1 peripheral circuits.
(Yes)
When BRIGHT CONTRAST of a
gradation pattern, is the abnormal area
shifted?
gradation pattern, is the abnormal area
shifted?
Check the IC10, IC11, and IC12
peripheral circuits.
peripheral circuits.
(Yes)
Display the RGB color gradation of the
output data lines of RN1~Rn12 and
check the line corresponding to the
abnormal color.
output data lines of RN1~Rn12 and
check the line corresponding to the
abnormal color.
(No)
Is the positive side of C28 at DC+5V?
(No)
Check the L10 peripheral circuits.
(Yes)
Are the oscillation circuits of X1 and X3
normal? (24MHz)
normal? (24MHz)
(No)
Check X1, X2, and the IC15 peripheral
oscillating circuit.
oscillating circuit.
(Yes)
Are the clock (R94) and the signal
output of DE (R95) normal?
output of DE (R95) normal?
Check the IC17 peripheral circuits,
CN10, CN11, and the LCD module.
CN10, CN11, and the LCD module.
(No)
Execute
(Yes)
Continued from
4
2