Mitsubishi LCD1855NX-BK, RDT181VBK, RDT181V, NX85LCD Service Manual

MITSUBISHI

DiamondPoint NX85LCD

COLOR MONIT OR

SER VICE MANUAL

CHASSIS NO. : CL-29
F ACT OR Y MODEL: LN801H
ID LABEL

MODEL No

: L182ET

MODEL: RDT181V(BK), NX85LCD

LCD1855NX-BK

CAUTION

BEFORE SERVICING THE UNIT,
READ THE SAFETY PRECAUTIONS IN THIS MANUAL.

1. LCD CHARACTERISTICS

Type : TFT SXGA LCD
Size : 18inch
Pixel Pitch : 0.2805(H) x 0.2805(V)
Color Depth : 8-bit, 16,777,216 colors
Electrical Interface : LVDS
Surface Treatment : Anti-Glare, Hard Coating(3H)
Operating Mode : Normally Black
Backlight Unit : Six-CCFL (Cold Cathode

Fluorescent Lamp)

2. OPTICAL CHARACTERISTICS

2-1. Viewing Angle by Contrast Ratio

≥

10

Left : -60° min., -80°(Typ)
Right : +60° min., +80°(Typ)
Top : +60° min., +80°(Typ)
Bottom : -60° min., -80°(Typ)

2-2. Luminance : 200(min), 250(Typ)
2-3. Contrast Ratio : 200(min), 350(Typ)

3. SIGNAL (Refer to the Timing Chart)

3-1. Sync Signal

• Type : Separate, Positive/Negative
Composite, SOG (Sync On Green)
Digital

3-2. Video Input Signal

1) Type : R, G, B Analog

2) Voltage Level : 0~0.71 V

a) Color 0, 0 : 0 Vp-p
b) Color 7, 0 : 0.467 Vp-p
c) Color 15, 0 : 0.714 Vp-p

3) Input Impedance : 75 Ω

3-3. Operating Frequency

Horizontal : 30 ~ 80kHz
Vertical : 56 ~ 85Hz(Limited to 75Hz by EDID)

4. POWER SUPPLY

4-1. Power Adaptor(Built-in Power)

Input : AC 100~240V, 50/60Hz , 1.0A

4-2. Power Consumption

5. ENVIRONMENT

5-1. Operating Temperature: 5°C~35°C (41°F~95°F)

(Ambient)

5-2. Relative Humidity : 10%~80%

(Non-condensing)

5-3. MTBF : 50,000 Hours(Min)

6. DIMENSIONS (with TILT/SWIVEL)

Width : 406 mm (15.98'')
Depth : 215 mm (8.46'')
Height : 427 mm (16.81'')

7. WEIGHT (with TILT/SWIVEL)

Net. Weight : 8.2kg (18.08 lbs)
Gross Weight : 11kg (24.25 lbs)

CONTENTS

SPECIFICATIONS

- 2 -

SPECIFICATIONS ................................................... 2

SERIAL NUMBER INFORMATION ......................... 4

PRECAUTIONS ....................................................... 5

TIMING CHART ....................................................... 6

OPERATING INSTRUCTIONS ................................ 7

WIRING DIAGRAM ................................................. 8

BLOCK DIAGRAM ................................................... 9

DESCRIPTION OF BLOCK DIAGRAM...................10

ADJUSTMENT ...................................................... 12

INSPECTION.......................................................... 17

TROUBLESHOOTING GUIDE .............................. 22

PRINTED CIRCUIT BOARD................................... 27

EXPLODED VIEW...................................................30

REPLACEMENT PARTS LIST ...............................32

PIN CONFIGURATION............................................37

SCHEMATIC DIAGRAM......................................... 39

MODE

POWER ON (NORMAL)

STAND-BY

SUSPEND

DPMS OFF

POWER S/W OFF

H/V SYNC

ON/ON
OFF/ON
ON/OFF

OFF/OFF

-

POWER CONSUMPTION

less than 53 W

less than 3 W
less than 3 W

less than 3 W
less than 2 W

LED COLOR

GREEN
AMBER
AMBER
AMBER

OFF

VIDEO

ACTIVE

OFF
OFF
OFF

-

Signal Connector Pin Assignment

Pin Signal (DVI-D)

1
2
3
4
5
6
7
8

9
10
11
12
13
14
15

T. M. D. S. Data2­T. M. D. S. Data2+
T. M. D. S. Data2/4 Shield
T. M. D. S. Data4­T. M. D. S. Data4+
DDC Clock
DDC Data
NOT USED
T. M. D. S. Data1­T. M. D. S. Data1+
T. M. D. S. Data1/3 Shield
T. M. D. S. Data3­T. M. D. S. Data3+
+5V Power
Ground

(return for +5V,

H. Sync. and V. Sync.)

Pin Signal (DVI-D)

1

8

9

17

24

16

16
17
18
19
20
21
22
23
24

Hot Plug Detect
T. M. D. S. Data0­T. M. D. S. Data0+
T. M. D. S. Data0/5 Shield
T. M. D. S. Data5­T. M. D. S. Data5+
T. M. D. S. Clock Shield
T. M. D. S. Clock+
T. M. D. S. Clock-

T. M. D. S. (Transition Minimized Differential Signaling)

• DVI-D Connector (Digital)

SERIAL NUMBER INFORMATION

206100001

: Y MM C SSSSS

Overprinting

(1)

(1) : Year code of Production(Last Number of year)

(2)

ex)2000 0, 2001 1, 2002 2

(3)

(4)

(3) : Classification code

ex) RDT181V(BK) Model 1

(4) : Serial Number : This Serial number doesn’t reset at each month.

ex) 00001~01234, 01235~99999, 00001~00010.....

(2) : Month code of Production

Month 1 2 3456789101112
Number 01 02 03 04 05 06 07 08 09 10 11 12

- 5 -

WARNING FOR THE SAFETY-RELATED COMPONENT.

• There are some special components used in LCD
monitor that are important for safety. These parts are

marked on the schematic diagram and the
replacement parts list. It is essential that these critical

parts should be replaced with the manufacturer’s
specified parts to prevent electric shock, fire or other
hazard.

• Do not modify original design without obtaining written
permission from manufacturer or you will void the
original parts and labor guarantee.

TAKE CARE DURING HANDLING THE LCD MODULE
WITH BACKLIGHT UNIT.

• Must mount the module using mounting holes arranged
in four corners.

• Do not press on the panel, edge of the frame strongly
or electric shock as this will result in damage to the
screen.

• Do not scratch or press on the panel with any sharp
objects, such as pencil or pen as this may result in
damage to the panel.

• Protect the module from the ESD as it may damage the
electronic circuit (C-MOS).

• Make certain that treatment person’s body are
grounded through wrist band.

• Do not leave the module in high temperature and in
areas of high humidity for a long time.

• The module not be exposed to the direct sunlight.

• Avoid contact with water as it may a short circuit within

the module.

• If the surface of panel become dirty, please wipe it off
with a softmaterial. (Cleaning with a dirty or rough cloth
may damage the panel.)

WARNING

BE CAREFUL ELECTRIC SHOCK !

• If you want to replace with the new backlight (CCFL) or
inverter circuit, must disconnect the AC adapter
because high voltage appears at inverter circuit about
650Vrms.

• Handle with care wires or connectors of the inverter
circuit. If the wires are pressed cause short and may
burn or take fire.

PRECAUTION

CAUTION

Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.

TIMING CHART

- 6 -

VIDEO

SYNC

B

D

C

F

E

A

<< Dot Clock (MHz), Horizontal Frequency (kHz), Vertical Frequency (Hz), Horizontal etc... (µs), Vertical etc... (ms) >>

H + 31.469 900 720 54 108 18
V – 70.082 449 350 60 2 37

H – 37.861 832 640 128 40 24
V – 72.809 520 480 28 3 9

H – 31.469 800 640 48 96 16
V – 59.940 525 480 33 2 10
H – 35.000 864 640 96 64 64
V – 66.670 525 480 39 3 3

H – 31.469 900 720 54 108 18
V + 70.082 449 400 35 2 12

H – 37.500 840 640 120 64 16
V – 75.000 500 480 16 3 1
H + 35.156 1024 800 128 72 24
V + 56.250 625 600 22 2 1
H + 37.879 1056 800 88 128 40
V + 60.317 628 600 23 4 1
H + 48.077 1040 800 64 120 56
V + 72.188 666 600 23 6 37
H + 46.875 1056 800 160 80 16
V + 75.000 625 600 21 3 1
H – 49.725 1152 832 224 64 32
V – 74.550 667 624 39 3 1
H – 48.363 1344 1024 160 136 24
V – 60.004 806 768 29 6 3
H – 56.476 1328 1024 144 136 24
V – 70.069 806 768 29 6 3
H + 60.023 1312 1024 176 96 16
V + 75.029 800 768 28 3 1
H + 63.981 1688 1280 248 112 48
V + 60.020 1066 1024 38 3 1

H + 79.976 1688 1280 248 144 16
V + 75.025 1066 1024 38 3 1

Mode

H/V

Sort

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

28.324

28.324

25.175

30.240

31.500

31.500

36.000

40.000

50.000

49.500

57.283

65.0

75.000

78.750

108.000

135.000

720x350

70Hz

640x480

73Hz

640x480

60Hz

640x480

66Hz

720x400

70Hz

640x480

75Hz

800x600

56Hz

800x600

60Hz

800x600

72Hz

800x600

75Hz

832x624

75Hz

1024x768

60Hz

1024x768

70Hz

1024x768

75Hz

1280x1024

60Hz

1280x1024

75Hz

Sync

Polarity

Frequency

Dot

Clock

Total Period

(E)

Video Active Time

(A)

Sync Duration

(D)

Front Portch

(C)

Back Porch

(F)

Resolution

OPERATING INSTRUCTIONS

MITSUBISHI

DiamondPoint NX85LCD

FRONT VIEW

Front Control Panel

DVI Connect

REAR VIEW

Power Connect

D-Sub Signal
Connect

Front Control Panel

1. Power ON/OFF Button

Use this button to turn the monitor on or off.

2. Power Indicator

This indicator lights up green when the monitor
operates normally. If the display is in DPM(Energy

Saving)mode, this indicator color change to amber.

3. MENU Button

Use these buttons to enter or exit the On Screen Display.

213 46 5

4.

▼▲◀▶

Use these buttons to choose or adjust items in the On Screen
Display.

Button

5. AUTO/SELECT Button

Automatically adjust vertical position, horizontal position, pixel
clock and phase.
Use this button to enter a selection in the On Screen Display.

6. SOURCE Button

Use this button to make Dsub or DVI connector active.
This feature is used when two computers are connected to the
monitor. The default setting is Dsub.

- 7 -

MODULE

MAIN PCB

MATAL FRAME

J702

J801

J705

P902

J710

CN7

CN3

CN2

CN1

CN6

CN5

CN4

CN_C01

CN301

CN_C02

Connector Ass’y P/N:

6631T20015R

Connector Ass’y P/N:

6631T25008Q

Connector Ass’y P/N:

6631T20008U

Connector Ass’y P/N:

6631T11012P

D-SUB

DVI-D

Gm5020

including

(ADC / TMDS Rx )

LVDS

(LVDS823)

Memory

(KM416S102BT)

H/V Sync

Micom

68HC08-BD48

M-CLK

Out - CLK

DE ,H/V Sync out

R,G,B /Odd

LCD Module

R,G,B
differential

Data 48 Bit

Address

Inverter CTL

Module CTL

R,G,B

Inverter

Digital Signal

3.3V

Reg.

DVDD 3. 3 V
AVDD 3.3V

12V

Power CTL

12V

2.5V
Reg.

DVDD2.5V
AV DD2.5V

3.3V

Reg.

PVDD 3. 3 V

3.3 VM

5V 5V

5V

H/V Sync

H/V-Sync

3.3 VM

Power Board

12V

5V

AV DD3.3V

AV DD2.5V

- 10 -

DESCRIPTION OF BLOCK DIAGRAM

1. Video Controller Part(GM5020).

This part amplifies the level of video signal for the anolog to digital conversion and converts from the analog video
signal to the digital video signal using a pixelclock.
The pixel clock for each mode is generated by the PLL.
The range of the pixel clock is from 25MHz to 135MHz.
This part consists of the Scaler and frame buffers which converts frame rate of input signal to 60Hz frame rate.
The Scaler gets the video signal converted analog to digital, interpolates input to1280 X 1024 resolution signal and
outputs 8-bit R, G, B signal to transmitter.
Especially pre-amp / ADC / Video controller are merged to one chip ‘Gm5020’ by Genesis.
Also FRC is separate.

2. Display Data Transmitter Part(LVDS).

This part transmit digital signal from the Scaler to the receiver of module.

3. Power Part.

This part consists of the one 5V, two 3.3V and one 2.5 regulators to convert power which is provided 12V, 5V in
Power Board.
12V is provided for inverter and LCD Panel, 5V is provided for Micom.
Also, 5V is converted 3.3V and 2.5V by regulator. Converted power is provided for IC in the main board.

4. MICOM Part.

This part consists of EEPROM IC which stores control data, Reset IC and the Micom.
The Micom distinguishes polarity and frequency of the H/V sync are supplied from signal cable.
The controlled data of each modes is stored in EEPROM.

5. Inverter

The inverter converts from DC12V to AC 600Vrms and operate back-light lamp of module.

- 11 -

EMI

COMPONENTS

LINE

100 ~ 240V

INPUT RECTIFIE R

AND FILTER

ENERGY

TRANSFER

OUTPUT RECTIFIE R

AND FILTER

12V

5V

GND

SIGNAL

COLLECTION

PHOTO-COUPLER

ISOLATION

PWM CONTROL

CIRCUIT

HVDC

100KHz

PRIMARY

SECONDARY

50 ~ 60Hz

Operation description_Power

1. EMI components.

This part contains of EMI components to comply with global marketing EMI standards like FCC, VCCI CISPR,
the circuit included a line-filter, across line capacitor and of course the primary protection fuse.

2. Input rectifier and filter.

This part function is for transfer the input AC voltage to a DC voltage through a bridge rectifier and a bulk capacitor.

3. Energy Transfer.

This part function is transfer the primary energy to secondary through a power transformer.

4. PWM control circuit.

This part function is to make a pulse width modulation control and to provide the driver signal to power switch, to
adjust the duty cycle during different AC input and output loading condition to achieve the dc output stabilize, and
also the over power protection is also monitor by this part.

5. Photo-Coupler isolation.

This part function is to feed back the dc output changing status through a photo transistor to primary controller to
achieve the stabilized dc output voltage.

6. Signal collection.

This part function is to collect the any change from the dc output and feed back to the primary through photo
transistor.

7. Output rectifier and filter.

This part function is to achieve the dc output voltage stabilize.

ADJUSTMENT

- 12 -

1. Application

This specification shall be applied to the adjustment and inspection of the LN801H.

2. Adjustment Setup

All adjustment are thoroughly checked and corrected when the monitor leaves the factory, but sometimes several
minor adjustment may be required.
Adjustment should be following procedure and after more than 30 minutes.
Unless otherwise specified, adjustment shall be carried out under the following conditions.

- Input Power: 100~240V /50~60Hz

- Input Signal: 1280 X1024 @ 60Hz default

- Aging Time: More than 30 Minutes

- Aging Temperature: 10~35 degrees

- Adjustment equipment and equipment connection setup.

Refer to figure 1.

VG819 or equivalent,

1) IBM compatible PC

2) Adjustment program for LN801H.

3) Adapter Box

220

IBM
Compatible PC

Video Signal
Generator

PARALLEL PORT

Power inlet (required)

Power LED

ST Switch

Power Select Switch
(110V/220V)

Control Line

Not used

RS232C

PARALLEL

V-SYNC

POWER

ST

VGS

MONITOR

E

E

V-Sync On/Off Switch
(Switch must be ON.)

F

F

A

A

B

B

C

C

15

10

5

5

69

1

1

1

14

13

25

6

5V

5V

5V

4.7K

4.7K

4.7K

74LS06

74LS06

OFF ON

OFF

ON

11

Figure 1. Cable Connection

3. Adjustment

3-1. Initialization and Aging

Prior to adjustment of this model, more than 30 minutes of aging shall be carried out.

1) Display any pattern at any Mode.

2) Run adjustment program for LN801H on the IBM compatible PC.

3) Select EEPROM → ALL INIT command and Enter.

4) This will make all data to default state and make aging mode.

5) Remove signal cable from the monitor.

<< LCD IIC ADJUST. PROGRAM :LCD185~1. DAT >>

MENU Move : Arrow or Space MENU Select : Enter

COLOR ADJ COMMAND EDIT EEPROM QUIT

DIST. ADJ

<< LCD IIC ADJUST. PROGRAM :LCD185~1. DAT >>

MENU Move : Arrow or Space Quit : ESCMENU Select : Enter

COLOR ADJ COMMAND EDIT EEPROM QUITDIST. ADJ

ALL Init.
EDID(A) WR
EDID(D) WR
EDID Read
EEPROM Read

3-2. Adjustment of Factory Preset Mode.

<< LCD IIC ADJUST. PROGRAM :LCD185~1. DAT >>

MENU Move : Arrow or Space Quit : ESCMENU Select : Enter

COLOR ADJ COMMAND EDIT EEPROM QUITDIST. ADJ

BIAS CAL
DRIVE CAL

<< LCD IIC ADJUST. PROGRAM :LCD185~1. DAT >>

MENU Move : Arrow or Space Quit : ESCMENU Select : Enter

COLOR ADJ COMMAND EDIT EEPROM QUITDIST. ADJ

BIAS CAL
DRIVE CAL

1) It’s not necessary for preset mode adjustment.
All preset mode data shall be written to EEPROM at initial power on.

2) IMPORTANT

At the initial Power turn on, maintain power on status more than 3 seconds.

3-3. Adjustment for White Balance

1) Display (Full black pattern) at SXGA 60Hz.

2) Set External Bright to MAX position and Contrast to 80 Position.

3) Select COLOR ADJ → BIAS CAL command and Enter.

4) No attempt to manually adjust, BIAS data is automatically adjusted and saved to the EEPROM.
If the message of "AUTO OK OK" is displayed at front of screen,
The adjustment is succeeded.
If the message of "AUTO ERROR" is displayed at front of screen, because the adjustment is failed, do adjust
again.

5) Display (Full white pattern) at SXGA 60Hz.

6) Select DRIVE CAL command and Enter.

7) 6500K and 9300k are automatically adjusted and saved to the EEPROM.
If the message of "AUTO OK OK" is displayed at front of screen,
The adjustment is succeeded.
If the message of "AUTO ERROR" is displayed at front of screen, because the adjustment is failed. So do
adjust again.

- 14 -