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MFM-HT75W/HT95
US Model
Canadian Model
AEP Model
E Model
TFT LCD COLOR COMPUTER DISPLAY
SERVICE MANUAL
2
PROG
PROG


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MFM-HT75W/HT95 (E)
­ 2 ­
1. LCD CHARACTERISTICS
Type
: TFT Color LCD Module
Size
: 17 inch (MFM-HT75W)
19 inch (MFM-HT95)
Pixel Pitch
: 0.2895(H) x 0.2895(V) (MFM-HT75W)
0.294 (H) x 0.294 (V) (MFM-HT95)
Color Depth
: 16.2M colors (MFM-HT75W)
16.7M colors (MFM-HT95)
Electrical Interface
: LVDS
Surface Treatment
: Clear Black, Anti-Static, Non diffusing
Operating Mode
: Normally Black
Backlight Unit
: 4CCFL(MFM-HT75W)
6CCFL(MFM-HT95)
2. OPTICAL CHARACTERISTICS
2-1. Viewing Angle by Contrast Ratio
10
MFM-HT75W
:
85
° Typical
MFM-HT95
:
89
° Typical
2-2. Luminance
: 450min(Typ)
2-3. Contrast Ratio
: 800 : 1 (MFM-HT75W)
600 : 1 (MFM-HT95)
3. SIGNAL (Refer to the Timing Chart)
3-1. Sync Signal
· Type
: Separate Sync,
SOG (Sync On Green)
Composite Sync, 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
3-3. Operating Frequency
(MFM-HT75W)
Horizontal
: 28 ~ 69kHz (Digital: ~48kHz)
Vertical
: 48 ~ 85Hz (Digital: 60Hz)
(MFM-HT95)
Horizontal
: 28 ~ 86kHz (Digital: ~64kHz)
Vertical
: 48 ~ 85Hz (Digital: 60Hz), 1280x1024
48 ~ 75Hz (Digital: 60Hz), 1280x1024
4. Max. Resolution
Analog
: 1280 x 1024 / 75Hz
DVI Analog/ Digital
: 1280 x 768 / 60Hz(MFM-HT75W)
1280 x 1024/ 60Hz(MFM-HT95)
5. POWER SUPPLY
5-1. Power : AC 100~240V, 50/60Hz , 1.0A
5-2. Power Consumption
6. ENVIRONMENT
6-1. Operating Temperature
: 5
°C~35°C
6-2. Relative Humidity
: 10%~80%
7. DIMENSIONS (with TILT/SWIVEL)
(MFM-HT75W)
Width
: 451mm
Depth
: 176 mm
Height
: 353.5 mm
(MFM-HT95)
Width
: 467mm
Depth
: 185 mm
Height
: 437 mm
8. WEIGHT (with TILT/SWIVEL)
(MFM-HT75W)
Net. Weight
: 6.3kg
Gross Weight
: 9.28kg
(MFM-HT95)
Net. Weight
: 7.8kg
Gross Weight
: 11.25kg
CONTENTS
SPECIFICATIONS
SPECIFICATIONS ................................................... 2
PRECAUTIONS.........................................................3
TIMING CHART ....................................................... 7
OPERATING INSTRUCTIONS ................................10
DISASSEMBLY ..................................................... 13
SERVICE OSD ........................................................14
EXPLODED VIEW...................................................15
EXPLODED VIEW PARTS LIST .............................16
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 68 W(MFM-HT-75W)
less than 74 W(MFM-HT-95)
less than 1.2 W
less than 1.2 W
LED COLOR
GREEN
AMBER
RED
VIDEO
ACTIVE
OFF
OFF
OFF
-
(100/50Hz, 240V/60Hz)


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MFM-HT75W/HT95 (E)
­ 3 ­
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. Data2-
T. M. D. S. Data2+
T. M. D. S. Data2/4 Shield
T. M. D. S. Data4-
T. M. D. S. Data4+
DDC Clock
DDC Data
Analog Vertical Sync.
T. M. D. S. Data1-
T. M. D. S. Data1+
T. M. D. S. Data1/3 Shield
T. M. D. S. Data3-
T. 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. Data0-
T. M. D. S. Data0+
T. M. D. S. Data0/5 Shield
T. M. D. S. Data5-
T. 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
PRECAUTION
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.
Leakage Current Hot Check Circuit
CAUTION
Please use only a plastic screwdriver to protect yourself
from shock hazard during service operation.
1.5 Kohm/10W
To Instrument's
exposed
METALLIC PARTS
Good Earth Ground
such as WATER PIPE,
CONDUIT etc.
AC Volt-meter


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MFM-HT75W/HT95 (E)
­ 4 ­
SERVICING PRECAUTIONS
CAUTION: Before servicing receivers covered by this
service manual and its supplements and addenda, read
and follow the
SAFETY PRECAUTIONS on page 3 of this
publication.
NOTE: If unforeseen circumstances create conflict
between the following servicing precautions and any of the
safety precautions on page 3 of this publication, always
follow the safety precautions. Remember: Safety First.
General Servicing Precautions
1. Always unplug the receiver AC power cord from the AC
power source before;
a. Removing or reinstalling any component, circuit
board module or any other receiver assembly.
b. Disconnecting or reconnecting any receiver electrical
plug or other electrical connection.
c. Connecting a test substitute in parallel with an
electrolytic capacitor in the receiver.
CAUTION: A wrong part substitution or incorrect
polarity installation of electrolytic capacitors may
result in an explosion hazard.
d. Discharging the picture tube anode.
2. Test high voltage only by measuring it with an
appropriate high voltage meter or other voltage
measuring device (DVM, FETVOM, etc) equipped with
a suitable high voltage probe.
Do not test high voltage by "drawing an arc".
3. Discharge the picture tube anode only by (a) first
connecting one end of an insulated clip lead to the
degaussing or kine aquadag grounding system shield
at the point where the picture tube socket ground lead
is connected, and then (b) touch the other end of the
insulated clip lead to the picture tube anode button,
using an insulating handle to avoid personal contact
with high voltage.
4. Do not spray chemicals on or near this receiver or any
of its assemblies.
5. Unless specified otherwise in this service manual,
clean electrical contacts only by applying the following
mixture to the contacts with a pipe cleaner, cotton-
tipped stick or comparable non-abrasive applicator;
10% (by volume) Acetone and 90% (by volume)
isopropyl alcohol (90%-99% strength)
CAUTION: This is a flammable mixture.
Unless specified otherwise in this service manual,
lubrication of contacts in not required.
6. Do not defeat any plug/socket B+ voltage interlocks
with which receivers covered by this service manual
might be equipped.
7. Do not apply AC power to this instrument and/or any of
its electrical assemblies unless all solid-state device
heat sinks are correctly installed.
8. Always connect the test receiver ground lead to the
receiver chassis ground before connecting the test
receiver positive lead.
Always remove the test receiver ground lead last.
9.
Use with this receiver only the test fixtures specified in
this service manual.
CAUTION: Do not connect the test fixture ground strap
to any heat sink in this receiver.
Electrostatically Sensitive (ES) Devices
Some semiconductor (solid-state) devices can be
damaged easily by static electricity. Such components
commonly are called
Electrostatically Sensitive (ES)
Devices. Examples of typical ES devices are integrated
circuits
and
some
field-effect
transistors
and
semiconductor "chip" components. The following
techniques should be used to help reduce the incidence of
component damage caused by static by static electricity.
1. Immediately before handling any semiconductor
component or semiconductor-equipped assembly, drain
off any electrostatic charge on your body by touching a
known earth ground. Alternatively, obtain and wear a
commercially available discharging wrist strap device,
which should be removed to prevent potential shock
reasons prior to applying power to the unit under test.
2. After removing an electrical assembly equipped with
ES devices, place the assembly on a conductive
surface such as aluminum foil, to prevent electrostatic
charge buildup or exposure of the assembly.
3. Use only a grounded-tip soldering iron to solder or
unsolder ES devices.
4. Use only an anti-static type solder removal device.
Some solder removal devices not classified as "anti-
static" can generate electrical charges sufficient to
damage ES devices.
5. Do not use freon-propelled chemicals. These can
generate electrical charges sufficient to damage ES
devices.
6. Do not remove a replacement ES device from its
protective package until immediately before you are
ready to install it. (Most replacement ES devices are
packaged with leads electrically shorted together by
conductive foam, aluminum foil or comparable
conductive material).
7. Immediately before removing the protective material
from the leads of a replacement ES device, touch the
protective material to the chassis or circuit assembly
into which the device will be installed.
CAUTION: Be sure no power is applied to the chassis
or circuit, and observe all other safety precautions.
8. Minimize bodily motions when handling unpackaged
replacement ES devices. (Otherwise harmless motion
such as the brushing together of your clothes fabric or
the lifting of your foot from a carpeted floor can
generate static electricity sufficient to damage an ES
device.)


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MFM-HT75W/HT95 (E)
­ 5 ­
General Soldering Guidelines
1. Use a grounded-tip, low-wattage soldering iron and
appropriate tip size and shape that will maintain tip
temperature within the range or 500 F to 600 F.
2. Use an appropriate gauge of RMA resin-core solder
composed of 60 parts tin/40 parts lead.
3. Keep the soldering iron tip clean and well tinned.
4. Thoroughly clean the surfaces to be soldered. Use a
mall wire-bristle (0.5 inch, or 1.25cm) brush with a
metal handle.
Do not use freon-propelled spray-on cleaners.
5. Use the following unsoldering technique
a. Allow the soldering iron tip to reach normal
temperature.
(500 F to 600 F)
b. Heat the component lead until the solder melts.
c. Quickly draw the melted solder with an anti-static,
suction-type solder removal device or with solder
braid.
CAUTION: Work quickly to avoid overheating the
circuitboard printed foil.
6. Use the following soldering technique.
a. Allow the soldering iron tip to reach a normal
temperature (500 F to 600 F)
b. First, hold the soldering iron tip and solder the strand
against the component lead until the solder melts.
c. Quickly move the soldering iron tip to the junction of
the component lead and the printed circuit foil, and
hold it there only until the solder flows onto and
around both the component lead and the foil.
CAUTION: Work quickly to avoid overheating the
circuit board printed foil.
d. Closely inspect the solder area and remove any
excess or splashed solder with a small wire-bristle
brush.
IC Remove/Replacement
Some chassis circuit boards have slotted holes (oblong)
through which the IC leads are inserted and then bent flat
against the circuit foil. When holes are the slotted type,
the following technique should be used to remove and
replace the IC. When working with boards using the
familiar round hole, use the standard technique as
outlined in paragraphs 5 and 6 above.
Removal
1. Desolder and straighten each IC lead in one operation
by gently prying up on the lead with the soldering iron
tip as the solder melts.
2. Draw away the melted solder with an anti-static
suction-type solder removal device (or with solder
braid) before removing the IC.
Replacement
1. Carefully insert the replacement IC in the circuit board.
2. Carefully bend each IC lead against the circuit foil pad
and solder it.
3. Clean the soldered areas with a small wire-bristle
brush. (It is not necessary to reapply acrylic coating to
the areas).
"Small-Signal" Discrete Transistor
Removal/Replacement
1. Remove the defective transistor by clipping its leads as
close as possible to the component body.
2. Bend into a "U" shape the end of each of three leads
remaining on the circuit board.
3. Bend into a "U" shape the replacement transistor leads.
4. Connect the replacement transistor leads to the
corresponding leads extending from the circuit board
and crimp the "U" with long nose pliers to insure metal
to metal contact then solder each connection.
Power Output, Transistor Device
Removal/Replacement
1. Heat and remove all solder from around the transistor
leads.
2. Remove the heat sink mounting screw (if so equipped).
3. Carefully remove the transistor from the heat sink of the
circuit board.
4. Insert new transistor in the circuit board.
5. Solder each transistor lead, and clip off excess lead.
6. Replace heat sink.
Diode Removal/Replacement
1. Remove defective diode by clipping its leads as close
as possible to diode body.
2. Bend the two remaining leads perpendicular y to the
circuit board.
3. Observing diode polarity, wrap each lead of the new
diode around the corresponding lead on the circuit
board.
4. Securely crimp each connection and solder it.
5. Inspect (on the circuit board copper side) the solder
joints of the two "original" leads. If they are not shiny,
reheat them and if necessary, apply additional solder.
Fuse and Conventional Resistor
Removal/Replacement
1. Clip each fuse or resistor lead at top of the circuit board
hollow stake.
2. Securely crimp the leads of replacement component
around notch at stake top.
3. Solder the connections.
CAUTION: Maintain original spacing between the
replaced component and adjacent components and the
circuit board to prevent excessive component
temperatures.