DOWNLOAD Sharp LL-T2020 (serv.man12) Service Manual ↓ Size: 1.7 MB | Pages: 34 in PDF or view online for FREE

LL-T2020

DISASSEMBLY AND ASSEMBLY

3 – 1

B

C

F

h

g

H

H

F

F

K

O

P

L

L

M

N

N

j

k

E

F

G

D

B

B

B

B

C

J

J

C

I

I

C

C

a

b

i

c

d

e

f

B

3

4

9

10

10

11

13

14

15

16

17

18

20

19

21

12

6

7

8

5

A

A

2

1

1) Remove the screw 

A

. Separate the display unit 

1

 from the stand unit 

2

.

1) Remove the screw 

B

 and then remove the display cover 

3

.

2) Remove the screw 

C

 and then remove the shield plate 

4

.

3) Remove the connector pin 

a

 and screw 

D

. Remove the USB board 

5

.

4) Remove the connectors (

b

, 

c

, 

d

, 

e

) and screws (

E

, 

F

). Remove the main board

6

.

5) Remove the screw 

G

 and then remove the PS switch cover 

7

.

6) Remove the connector 

f

 and screw 

H

. Remove the power supply board 

8

.

7) Remove the screw 

I

 and then remove the shield plate 

9

.

8) Remove the screw 

J

 and then remove the connector locking seat 

F

.

9) Remove the connectors (

g

, 

h

, 

i

) and screw 

K

. Remove the inverter board 

G

.

10) Remove the display mask unit 

H

.

11) Remove the screw (

L

, 

M

, 

N

, 

O

). Remove the LCD angles 

(

I

, 

J

, 

K

, 

L

).

12) Remove the board angles (

M

, 

N

).

13) Remove the connector 

j

 from the LCD unit 

O

.

14) Remove the screw 

P

. Remove the key 

switch angle 

P

.

15) Remove the key unit 

Q

 and then remove

the connector 

k

.

LL-T2020

DISASSEMBLY AND ASSEMBLY

3 – 2

A

A

B

E

F

H

J

J

J

G

H

I

I

B

B

C

D

D

1

2

3

4

5

6

7

9

10

14

15

16

17

12

13

11

8

1) Remove the screw 

A

. Separate the arm unit 

1

 from the base unit 

2

. 

2) Remove the cable cover 

3

.

3) Remove the screw 

B

 and then remove the base arm cover 

4

.

4) Remove the screw 

C

 and then remove the base arm cover 

5

.

5) Remove the screw 

D

 and then remove the base arm install angle 

6

.

6) Remove the screw 

E

 and then remove the slide guide 

7

.

7) Remove the base arm angle 

8

.

8) Remove the screw 

F

 and then remove the slide arm cover 

9

.

9) Remove the screw 

G

 and then remove the slide arm cover 

F

.

10) Remove the screw 

H

 and then remove the slide arm angle 

G

.

11) Remove the screw 

I

 and then remove the hinge covers (

H

, 

I

) from

the hinge unit 

J

.

12) Remove the screw 

J

 and then remove the stand base plates (

K

, 

L

)

from the stand cover 

M

.

LL-T2020

TROUBLESHOOTING

4 – 1

(Yes)

(Yes)

(Yes)

(Yes)

(Yes)

(Yes)

Green LED comes on when the power button is 
pressed?

The screen is displayed properly in each video 
mode?

AC cable is connected to the power supply 
unit?

Input signal port is the one to which analog 
signal cable is connected?

Test terminals LD401, LD402, and LD403 are 
DC+3.3V?

Test terminal LD623 changes its level when 
POWER switch is turned on and off?

Press INPUT key to switch over to the 
correct input signal port.

Check DC+5V power supply line (DV5A) 
and POWER_CTL1 signal and circuits  
around Q807.

Check the connection line of LD623, and 
check the CN601, SW PWB and cable.

Remove the analog signal cable. After a short 
while time, the LED color changes form green 
to orange. 

(Yes)

(Yes)

(No)

(No)

(Yes)

(Yes)

(No)

(No)

(No)

(No)

(Yes)

(Yes)

(No)

(No)

(No)

(No)

(No)

(Yes)

(No)

(Yes)

(Yes)

(No)

(No)

(No)

Perform  1

B/L is lit?

No error.

Check AC cable connection.

Check power supply unit switch.

Check circuits around IC601. 

Check circuits around IC801. 

Check circuits around IC401.

Check RESET circuit around IC602.

Check IC602 and clock circuit around X601.

Check SW101 and circuits around IC101.

The power supply unit is switched on?

SW101 is on 1st pin side?

Test terminal LD811 is DC+5V?

Test terminal LD815 is DC+5V? 

4th pin of IC602 is in H level (DC+5 V)?

C610-side terminal signal of X601 is normal?

Test terminal LD608 is DC+3.3V?

1

Perform  2

Perform  3

Perform  4

Check whether the following cables are connected correctly.
In addition, check whether the PCs video mode is properly set to the signal timing which meets this machine.

Attached cables
  Dedicated AC adapter
  Dedicated analog signal cable (DVI-A cable)
  Dedicated digital signal cable (DVI-D cable)

LL-T2020

TROUBLESHOOTING

4 – 2

(No)

(No)

(No)

(No)

(No)

(Yes)

(Yes)

(Yes)

(No)

(Yes)

(Yes)

(No)

(Yes)

(Yes)

(No)

(Yes)

(No)

(Yes)

(No)

(Yes)

(No)

(Yes)

(Yes)

(Yes)

(Yes)

(No)

(No)

The port from which the analog signal cable 
was removed is the input signal port selected?

48th pin and 49th pins of IC602 are in H level 
(DC+3.3V)?

LD613 and LD616 are in H level (about 
DC+1.9V)?

LD808 is less than DC+1.0V at maximum 
brightness?

1st pin of CN2, CN3, CN4, CN5, CN6, and CN7 
on inverter PWB unit is about 790 Vrms?  (Use 
caution not to get electric shock accident. Use 
a high-voltage probe (more than 100:1) for 
measuring voltage.)

Check analog signal cable and CN101 
(CN201).

Check SDA and SCL signals and circuits 
around IC402 and IC602.

Press INPUT key to switch over to the 
correct input signal port.

When CN802 cable is removed, check the 
LD801 is DC+12V.

Check inverter unit, inverter cable and their
connections.

Check the power unit and cable and their 
connections, and DC+12V power supply 
line.

Check BL_EN signal and circuits around 
CN802.

Check BRT_VR signal and circuits around 
IC604.

Signal waveforms of test terminals LD304, 
LD305 (LD317, LD318) are normal?

Signal waveforms of test terminals LD312, 
LD323 (LD313, LD324) are normal?

Signal waveforms of 31st and 32nd pins of 
IC402 are normal?

Check SW PWB and SW cable and their 
connections.

48th pin of IC602 is in H level (DC+3.3V)?

continued from  1

LD613 is H in level (about DC+1.9V)?

Check SW PWB and SW cable and their
connections.

Test terminal LD801 is DC+12V?

LD807 is in H level (DC+5V)?

Check lamp inside LCD module.

Check circuits around IC602.

Check Q601 and its surrounding circuits.

Replace inverter PWB unit with a new one.

Check circuits around IC602.

Check Q601 and its surrounding circuit.

Check circuits around IC301 and IC302.

2

3