Mitsubishi Electric MDT421S: Parts Name and Functions

English-6

ON

OFF

 UP (

) button

Activates the OSD menu when the OSD menu is turned-off.

Acts as   button to move the highlighted area up to select 

the adjustment with OSD menu.

 DOWN (

) button

Activates the OSD menu when the OSD menu is turned-off.

Acts as   button to move the highlighted area down to select 

the adjustment with OSD menu.

 EXIT button

Press the EXIT button to display the OSD menu while it isn’t 

being displayed. 

By pressing this button while the OSD menu is being 

displayed, you can move backward through the menu items. 

(You can move forward through the menu items using the 

INPUT button.) When you press this button at the Main Menu, 

the OSD menu disappears. (See page 23.)

 Brightness sensor (front, rear)

Sensor for the auto brightness function. (See page 25, 33.)

 Main Power Switch

On/Off Switch to turn main power on/off.

NOTE:  Control Key Lock Mode

This control completely locks out access to all Control Key 

functions.  To activate the control key lock function, press 

both of  “ ” and “

” and hold down simultaneously for 

more than 3 seconds.  To resume back to user mode, press 

both of “ ” and “

” and hold simultaneously for three (3) 

seconds.

 Remote control sensor and Power indicator

Receives the signal from the remote control (when using the 

wireless remote control).  See also page 9.

Glows green when the LCD monitor is in active and glows 

red when the LCD is in POWER OFF mode.  When the LCD is 

in power save mode, it will glow both green and red.  When 

SCHEDULE is enabled, it will blink green and glow red.  See 

page 21.  In the case of where a failure is detected, it will blink 

red.

 POWER button (

)

Switches the power on/off. See also page 20.

 MUTE button

Switches the audio mute ON/OFF.

 INPUT button

Displays the OSD menu for switching the video input.

(Select [RGB1], [RGB2], [RGB3], [RGB4], [RGB5]*, [RGB6], 

[DVD/HD], [VIDEO<S>] and [VIDEO] using the UP (

) and 

DOWN (

) buttons.) 

* : [RGB 5] becomes usable when the optional CAT5 Rx BOX 

is mounted.

By pressing this button while the OSD menu is being 

displayed, you can move forward through the menu items.  

(See page 23.)

 PLUS (+) button

Acts as (+) button to increase the adjustment with OSD menu.

Increase the audio output level when the OSD menu is turned 

off. 

 MINUS (-) button

Acts as (-) button to decrease the adjustment with OSD menu.  

Decreases the audio output level when the OSD menu is 

turned off.

Buttons, Switch, and Indicator 

Parts Name and Functions

English

English-7

 EXTERNAL SPEAKER TERMINAL

To output the audio signal for external speakers from  AUDIO 1, 

2, 3 jack or HDMI.

 AUDIO OUT

To output the audio signal from the AUDIO IN 1, 2, 3 jack or 

HDMI.

 AUDIO IN 1, 2, 3

To input the audio signal from external equipment such as a 

computer, VCR or DVD player.

 RGB 1 IN (HDMI)

To input the digital RGB signals from a computer, DVD player, 

etc.

* This connector does not support analog input.

  AUDIO is supported via HDMI.

 RGB 2 IN (DVI-D)

To input the digital RGB signals from a computer.

* This connector does not support analog input.

  AUDIO is supported via DVI-D.

 RGB 3 IN (mini D-Sub 15 pin)

To input the analog RGB signals from a computer or other 

RGB equipment.

 RGB OUT (mini D-Sub 15 pin)

To output the signal from RGB 3, 4 or 5 IN.

 RGB 6 IN (DISPLAY PORT)

To input the digital RGB signals from a computer.

 CAT5 Rx BOX slot

The CAT5 Rx BOX (option) is inserted in this slot. (See page 

12.)

NOTE:

Never connect network devices to the CAT5 IN and OUT 

connectors. If you do so, they may adversely affect with each 

other, causing breakdown.

 EXTERNAL CONTROL (mini D-Sub 9 pin) 

Connect the IN connector with the RS-232C OUT connector 

of the computer or a multi-connected MDT421S monitor. 

Connect the OUT connector with the RS-232C IN connector 

of a multi-connected MDT421S or MDT521S monitor. 

 VIDEO IN/OUT

VIDEO IN connector (BNC and RCA):

 To input a composite 

video signal.  BNC and RCA are not available at the same 

time. (Use only one input).

VIDEO OUT connector (BNC):

 To output the composite 

video signal from VIDEO IN connector.

S-VIDEO IN connector (MINI DIN 4 pin):

 To input the 

S-video (Y/C separate signal).

 RGB 4 IN / DVD/HD IN (BNC)

To input the analog RGB signals from a computer or other 

RGB equipment.

Connecting equipment such as a DVD player, HDTV device, 

or Laser disc player. See page 16, 18.

 AC IN connector

Connects with the supplied power cord.

Connectors and Terminals

(OUT)

(IN)

(OUT)

(IN)

(IN)

(IN)

English-8

Wireless Remote Control

 POWER button

Switches the power on/off. 

* If LED Power Indicator on the monitor is not glowing, then 

no controls will work.

 INPUT button

Selects from input signal, [RGB1] (HDMI),  [RGB2] (DVI-D),  

[RGB3] (D-SUB),  [RGB4] (BNC), [RGB5]* (CAT5), [RGB6] (DIS-

PLAY PORT), [DVD/HD] (YPbPr), [VIDEO<S>] and [VIDEO].

* : [RGB 5] becomes usable when the optional CAT5 Rx BOX 

is mounted. 

 PICTURE MODE button

Selects from picture mode, [HIGHBRIGHT],  [STANDARD],  

[sRGB], [CINEMA].  See page 21.

HIGHBRIGHT:

 for moving image such as Video

STANDARD:

 for images (Factory setting)

sRGB:

 for text based images

CINEMA:

 for movies 

 DISPLAY button

To switch the information OSD on/off.  See page 22.

 SET button

Acts as SET button with OSD menu.

 MINUS button decrease

Acts as (-) button to decrease the adjustment with OSD menu.

Small screen which adjusted “PIP” mode moves left.

 AUTO SETUP button

To enter the auto setup menu.  See page 28.

 AUDIO INPUT button

Press to change the audio source for each video source. The 

audio source is changed from [AUDIO1] to [AUDIO2], [AUDIO3] 

and [HDMI] in order. Note that you cannot select the audio 

source for [VIDEO<S>] or [VIDEO]. [HDMI] is selectable only 

when the video source is [RGB 1]. 

 PIP (Picture In Picture) button

ON/OFF button:

 PIP-ON/OFF.  See page 27, 33.

INPUT button:

 Select the “picture in picture” input signal.

CHANGE button:

 Replaces to the main picture and sub pic-

ture.

Note:

The “PIP” and “POP” modes do not function when the screen 

size is “CUSTOM” or “REAL”.

 STILL button

ON/OFF button:

 To switch the still picture mode on/off.

CAPTURE button:

 Updates the still picture.

 SIZE button

Selects picture size, [FULL], [NORMAL], [CUSTOM] , [DY-

NAMIC] and [REAL]. See page 21.

 MENU button

To switch the menu mode on/off.

 UP button

Acts as   button to move the highlighted area up to select 

the adjustment with OSD menu.

Small screen which adjusted “PIP” mode moves up.

 PLUS button increase

Acts as (+) button to increase the adjustment with OSD menu.

Small screen which adjusted “PIP” mode moves right.

 EXIT button

Turn to previous menu with OSD menu. 

 DOWN button

Acts as   button to move the highlighted area down to select 

the adjustment with OSD menu.

Small screen which adjusted “PIP” mode moves down.

 MUTE button

To switch the mute function on/off.

  VOLUME  button

Increases or decreases the audio output level. 

English

English-9

< Operating Range for the Remote 

Control >

Point the top of the remote control toward the LCD monitor's 

remote sensor during button operation.

Use the remote control within a distance of about 7 m/23 ft. 

from the front of the LCD monitor's remote control sensor 

and at a horizontal and vertical angle of within 30° within a 

distance of about 3 m/10 ft.

CAUTION:

Important, the remote control system may not function when 

direct sunlight or strong illumination strikes the remote control 

sensor of the LCD monitor, or when there is an object in the 

path.

< Handling the remote control >

*  Do not subject to strong shock.

*  Do not allow water or other liquid to splash the remote 

control. If the remote control gets wet, wipe it dry immedi-

ately.

*  Avoid exposure to heat and steam.

*  Other than to install the batteries, do not open the remote.

30°

30°