NEC MultiSync V520 User manual

MODELS MultiSync V520
MultiSync V521
MultiSync MV521
Diamond Scan 51
COLOR MONITOR (Model No. N0501 Series)
SERVICE MANUAL
Better Service
Better Reputation
Better Profit
/MITSUBISHI
NEC-MITSUBISHI ELECTRIC VISUAL SYSTEMS

PRODUCT SAFETY CAUTION
1. When parts replacement is required for servicing, always use the manufacturer’s specified
replacement.
2. Comply with all caution and safety-related notes on the product display chassis and picture tube.
3. When replacing the component, always be certain that all the components are put back in the
place.
4. When servicing display monitor unit, it is required that the provided lead dress is used in the high
voltage circuit area.
5. It is also recommended that shatter proof goggles are worn, when removing, installing and han-
dling the picture tube. People not equipped with the proper precautionary measures mentioned
should keep the picture tube away from body while handling.
6. As for a connector, pick and extract housing with fingers properly since a disconnection and
improper contacts may occur, when wires of the connector are led.
7. Use a proper screwdriver. If you use screwdriver that does not fit, you may damage the screws.
W A R N I N G
The SERVICE PERSONNEL should have the appropriate technical training knowledge
and experience necessary to :
Be familiar with specialized test equipment, and
Be careful to follow all safety procedures associated with high voltage CRT circuit
designs to minimize danger to themselves and their coworkers.
To avoid electrical chocks, this equipment should be used with an appropriate power
cord and be connected only to a properly grounded AC outlet
This equipment utilized a micro-gap power switch. Turn off the monitor by first pushing
the front panel power switch. Next, remove the power cord from the AC outlet.
To prevent fire or shock hazards, do not expose this unit to rain or moisture
This symbol warns the personnel that un-insulated voltage within the unit may
have sufficient magnitude to cause electric shock.
This symbol alerts the personnel that important literature concerning the
operation and maintenance of this unit has been included.
Therefore, it should be read carefully in order to avoid any problems.
!
!
!

CONTENTS
Page No.
PRECAUTIONS .................................................................................................................... 1
SPECIFICATIONS ................................................................................................................ 3
PIN ADJUSTMENT TABLE................................................................................................... 4
CONTROLS .......................................................................................................................... 5
ON-SCREEN MANAGER(OSM)........................................................................................... 7
SERIAL NUMBER INFORMATION..................................................................................... 12
DISASSEMBLY................................................................................................................... 13
ADJUSTMENT PROCEDURES ......................................................................................... 16
WRITE AND INSPECTION FOR PLUG AND PLAY COMMUNICATION........................... 28
TROUBLE SHOOTING....................................................................................................... 31
CIRCUIT DESCRIPTION.................................................................................................... 39
REPLACEMENT PARTS LIST............................................................................................ 74
1) MultiSync V520 Parts List .......................................................................................... 74
2) MultiSync V521 Different List..................................................................................... 94
3) MultiSync MV521 Different List.................................................................................. 96
4) Diamand Scan Different List ...................................................................................... 98
BLOCK DIAGRAMS............................................................................................................ 99
SCHEMATIC DIAGRAMS................................................................................................. 100

1 Precautions
Follow these safety and servicing precautions to prevent damage and to protect against potential hazards
such as electrical shock and X-rays.
1.1Safety Precautions
1-1-1 Warnings
1. For safety purpose, do not attempt to modify the circuit board, and always disconnect the AC power
before performing servicing on the monitor.
2. Operation of the monitor outside its cabinet or with the cover removed involves the risk of shock
hazard. Repair work on the monitor should only be attempted by service personnel who are thoroughly
familiar with all necessary safety precautions and procedures for working on high voltage equipment.
3. Do not lift the CRT by the neck. After completely discharging the high voltage anode, handle the CRT
only when wearing shatterproof goggles. Try to keep the CRT away from the body during handling.
4. High voltage should always be kept at the rated value, no higher. Only when high voltage is excessive
are X-rays capable of penetrating the shell of the CRT. Operation at high voltages may also cause
failure of the CRT or high voltage circuitry.
5. The CRT is especially constructed to limit X-ray emission to 0.5mR/HR at 300 microamperes anode
current. To ensure continued X-ray protection, replace the CRT with only the same or equivalent type
as the original, and adjust the anode’s voltage to the designated maximum rating, never to exceed.
1-1-2 Safety Checks
Before returning the monitor to the user, perform the following safety checks:
1. Inspect to make certain that each lead dress is not pinched or that hardware is not lodged between the
chassis and other metal parts in the monitor.
2. Inspect all protective devices such as nonmetallic control knobs, insulating materials, cabinet backs,
adjustment and compartment covers or shields, isolation resistor-capacitor networks, mechanical
insulators, etc.
3. AC Leakage Current Check
Always perform the AC Leakage Current Check on the exposed metal parts, including metal cabinets,
screwheads and control shafts, as follows:
a) Plug the AC line cord directly into a rated AC outlet. Do not use an isolation transformer during the
check.
b) Use an AC voltmeter with at least 5000 ohms per volt sensitivity as follows:
Connect a 1500 ohms, 10 watt resistor paralleled by a 0.15uF AC capacitor in series with all ex-
posed metal cabinet parts and a known earth ground, such as electrical conduct or electrical ground
connected to earth ground, as shown in the Figure 1-1. Measure the AC voltage across the combi-
nation of resistor and capacitor.
Figure 1-1. Set Up For AC Leakage Current Check
0.15ufd
1500 ohm 10 watt
To exposed metal
Cabinet part
To known
Earth ground
1

c) Reverse the AC plug at the AC outlet and repeat the steps for AC voltage measurements for each
exposed metal part.
d) Voltage reading must not exceed 0.3 volts RMS, equivalent to 0.2 milliampere AC. Any value ex-
ceeding this limits ill constitute a potential shock hazard and must be corrected immediately
1-1-3 Product Safety Notices
Many electrical and mechanical parts in this chassis have special safety-related characteristics which are
often not evident from visual inspection. The protection afforded by them may not be obtained by replac-
ing them with components rated for higher voltage, wattage, etc. Before replacing any of these
components, consult the Recommended Spare Parts List given at the end of this manual. Any of the
replacements that do not provide the same safety characteristics may result in shock, fire, X-ray emission
or other hazards.
1.2Servicing Precautions
Warning: An electrolytic capacitor installed with the wrong polarity might explode.
Caution: Before performing servicing covered by this service manual, read and follow the Safety Precau-
tions section of this manual.
Note: If unforeseen conflict between the following servicing precautions and of the safety
precautions, always follow the safety precautions
1. Follow closely the servicing precautions printed on the monitor cabinet and chassis.
2. Always unplug the AC power cord from the AC power source before removing or installing any compo-
nent or assembly, disconnection PCB plugs or connectors and connecting a test component in parallel
with a capacitor.
3. When replacing parts or circuit boards, clamp the lead wires around the unit before soldering.
4. When replacing a high wattage resistor (>0.5W metal oxide film resistor) in the circuit board, keep the
resistor about 1 cm (1/2 inch) away from the circuit board.
5. Keep wires away from the high voltage or high temperature components.
6. Keep wires in their original positions so as to minimize interference.
7. Always connect a test instrument’s ground lead to the instrument chassis ground before connecting the
positive lead; always remove the instrument’s ground lead last.
2

SPECIFICATION
NOTE: Technical specifications are subject to change without notice.
Monitor
Specifications N0501 Monitor Notes
Picture Tube
Dia
g
onal:
Viewable Ima
g
e Size:
Radius:
38cm(15inch)
35cm(13.8inch)
1080mm
90° deflection, 0.28mm trio dot pitch, medium
short persistence phosphor, multi-layered, anti-
static screen coating, semi-tint screen, Invar
Shadow Mask.
Input Si
g
nal Video:
S
y
nc: ANALOG 0.7Vp-p/75 Ohms Separate sync. TTL Level
Horizontal sync. Positive/
Negative
Vertical s
y
nc. Positive/Ne
g
ative
Displa
y
Colors Analo
g
input: Unlimited number of Colors Depends on display card used.
Synchronization
Range Horizontal: Vertical: 31 kHz to 70 kHz 55 Hz to 120 Hz Automatically Automatically
Resolutions Supported
Resolution based on horizontal and
vertical frequencies only
640 ×480 @ 60 to 120 Hz
800 ×600 @ 55 to 110 Hz
832 ×624 @ 55 to 106 Hz
1024
×
768 @ 55 to 87 Hz ……
1152 ×870 @ 55 to 77 Hz
1280 ×1024 @ 55 to 66 Hz
Some s
y
stems ma
y
not support all modes listed.
NEC cites recommended resolution at 85 Hz for
optimal display performance.
Active Displa
y
Area
(
Factor
y
Settin
g)
Horizontal:
Vertical: 270mm 203mm
Dependent upon signal timing used,
and does not include border area.
Active Display Area
(Full Scan) 280mm 210mm Dependent upon signal timing used, and does not include border area.
Power Supply AC 100 - 240V, 50 - 60Hz
Current Rating 1.3A @ 100 - 240V
Dimensions 360
(
W
)
×
380
(
H
)
×
381
(
D
)
mm
Weight (Net) 12.5 kg
Environmental Considerations
Operatin
g
Temperature:
Humidit
y
:
Altitude:
Stora
g
e Temperature:
Humidit
y
:
Altitude:
0° C to + 35° C
30% to 80%
0 to 3000 m
-20° C to + 60° C
10% to 90%
0 to 13700 m
3

PIN ASSIGNMENT
1 2 3 4 5
6 7 8 9 10
11 12 13 14 15
PIN NO. Mini D-SUB-15P
1RED
2 GREEN
3BLUE
4 GROUND
5 GROUND
6 GROUND
7 GROUND
8 GROUND
9NOPIN
10 GROUND
11 GROUND
12 SDA
13 H.SYNC.
14 V.SYNC.
15 SCL
4

CONTROLS
”SELECT”: To display OSM windows, mode changes, or activate the degaussing or OSM window
color selection.
CONTROL BUTTON (-,+): Without OSM — Adjust the contrast.
With OSM — Select icon and adjust.
”RESET”: Return the adjustment item to the factory setting.
Power indicator LED: The LED indicate Power management state.
POWER SWITCH: Push/push to turn the monitor on and off.
Power input: To connect with the power cord.
Signal input with the captive cable: To connect with personal computers’ analogue RGB output.
MultiSync V520


  


 
MultiSync V521

5

6
MultiSync MV521
Diamand Scan 51
  
  

OSD OPERATION
„P„P
„P„P
„PFUNCTION VALUE ADJUSTMENT
If OSD off, press UP key to increase Contrast value,
press DOWN key to decrease Contrast value.
press SELECT key to display OSD and Brightness icon is active (Fig. 1)
Fig. 1
Press UP key or DOWN key to select icon right or left and the selected icon display red color
If selected icon is DAC out, press SELECT key will display DAC value bar (fig 2)
User can press UP key or DOWN key to adjust DAC value.
Press SELECT key to close DAV value bar and UP key or DOWN key to select the other icon.
„P„P
„P„P
„PSPECIAL FUNCTION OPERATION
1. Degauss Active
If selected icon is degauss icon, press SELECT key to activate degauss (Fig. 3).
Fig. 2
Fig. 3
7

2. Color Temperature Select
If selected icon is 9300/7500/6500/user color icon, press SELECT key to select Color Temperature for
9300, 7500, 6500 or user defined (Fig 4 – 7).
3. OSD Color Select
If OSD icon is selected, press SELECT key to change OSD color, there are three kinds of OSD color can
be selected (Fig. 8 – 10).
Background white blue black
Action icon red red red
Normal icon black white white
Value bar blue yellow green
Fig. 4 Fig. 5
Fig. 6 Fig. 7
Fig. 8 Fig.9 Fig. 10
8

4. SYNC OSD Display
If EXIT icon is selected, press SELECT key to close OSD menu and then display sync information for 2
sec. This sync information will not be close until release SELECT key (Fig. 11).
5. Factory mode
Press SELECT key + UP key and power on, system enter factory mode.
OSD will display “FA” to indicate in factory mode (Fig. 12 – 13).
Operation of factory mode is same as normal mode except below 2 condition:
a. adjustment value is saved to user and factory area.
b. R, G, B value are saved to current color temperature.
Fig. 11
6. OSD Move Mode
Press DOWN key and power on, system enter OSD move mode, user can move OSD display position
in this mode.
Press SELECT key then OSD display following figure (Fig. 14) and only 3 icons OSD H-position / OSD
V-position / ESC can be selected.
Fig. 12 Fig. 13
Fig. 14
9

Function explanation
Brightness: Adjusts the overall image and background screen brightness.
Contrast: Adjusts the image brightness in relation to the background.
(Contrast control is also effective with “-, +” button even through
OSM window is not existing.)
RRed Color Control: Adjust the red contrast of the display.
GGreen Color Control: Adjust the green contrast of the display.
BBlue Color Control: Adjust the blue contrast of the display.
Horizontal position: Moves the image horizontally left or right.
Vertical position: Moves the image vertically up or down.
Horizontal size: Increases or decreases the horizontal size of the image.
Vertical size: Increases or decreases the vertical size of the image.
Pincushion/Barrel: Increases or decreases the curvature of the sides either
inward or outward.
Trapezoid: Increases or decreases the bottom of the screen to be the same as
the top.
Parallelogram: Increases or decreases the tilt of the sides either to the left or
right.
Bow (Pincushion Balance): Increases or decreases the curvature of the sides
either left or right.
Rotation: Rotate the image.
10

Degauss: Select the degauss icon on “Icon select window” and push “SELECT”
button. It will eliminate the stray magnetic field and correct the scan
the electron beam, and will affect the purity, focus, convergence.
Caution: Allow a minimum interval of 20 minutes to elapse between
uses of the degauss function.
9300KColor Temperature: Select the Color Temperature icon on “Icon Select Window”
and push “SELECT” button.
It can be switched the different color Temperature.
OSD: There are 3 background colors (Blue, Black, and white).
These can be selected by “SELECT” button after the selection of
“OSD” on “Icon select window”.
exit EXIT: To exit the OSM window. Select EXIT on “Icon select
window”. Then push “SELECT” button to exit OSM window.
Note: If you do not push buttons over 10 seconds in OSM condition, the window will
automatically disappear.
11

SERIAL NUMBER INFORMATION
Refer to the serial number information shown below.
Ex.) SERIAL NUMBER LABEL
MODEL N0501
SERIAL No. ∗∗∗∗∗∗∗∗∗
0Y1Y0000
00001 ~ on ward
(Start from 00001 ~ when
month is changed.)
Manufactured Year :
( Last digit )
Manufactured Month :
January to September 1 to 9
October X
November Y
December Z
Factory mark :
NPG CHINA “Y”
12
Control Code ··· E
Control Code ... A (Diamand
Scan 51)

DISASSEMBLY
Tilt / swivel base fixing, removing
Fixing
This product consists of the MultiSync monitor and the tilt / swivel base.
When fixing the tilt / swivel base to the MultiSync monitor, please follow the steps below.
• Push the six hooks of the tilt / swivel base into the six holes at the bottom of the MultiSync
monitor.
• Then slide the tilt / swivel base forward.
• Then the latch above the tilt / swivel base engages it is ss
ss
s
ee
ee
e
cc
cc
c
uu
uu
u
rr
rr
r
ee
ee
e
..
..
.
Removing
Please removing the tilt / swivel base when transporting for repair.
• Push down the latch of the MultiSync monitor and pull out the tilt / swivel base.
• Slide backward the tilt / swivel base from the front of the MultiSync monitor.
•Pull out the tilt / swivel base from the holes of the MultiSync monitor.
13

Cabinet Back
1.Turn the monitor CRT face down on a clean static
free surface to prevent scratching CRT face.
2.Remove the screw “b”.
3.Raise the signal cable vicinity of a cabinet back
and lightly hit part (figure 1 reference) of a top of
the cabinet back and remove the cabinet back.
Cabinet Back
Screw “b”
Hitting Position
Cabinet Back
Fig. 1
14

MAIN BOARD and CRT BOARD
1. Unsolder the GND wire from MAIN BOARD ASSY
2. Disconnect the connector “P201”, “P202”, “S204”
and “S205” from the CRT BOARD ASSY.
3. Disconnect the CRT BOARD ASSY from the CRT
4. Disconnect the connector “S301” and “P102” from
the MAIN BOARD ASSY.
5. Remove the Anode Cap from the CRT.
NOTE:
Carefully discharge the CRT anode by shorting it
to ground before removing Anode Cap.
6. Lift up the MAIN BOARD ASSY from the Cabinet
Front ASSY.
CRT BOARD ASSY
MAIN BOARD ASSY
CRT
15

ADJUSTMENT SPECIFICATIONS
TABLE OF CONTENTS
Page
(1) Adjustment & Inspection Tools .......................................................................................................... 17
(2) Timing Table ...................................................................................................................................... 17
(3) Definition for Normal Condition ......................................................................................................... 17
(4) Hot Key Operation............................................................................................................................. 17
(5) B+ Adjustment ................................................................................................................................... 18
(6) X-ray Test .......................................................................................................................................... 18
(7) H. V. Adjustment ............................................................................................................................... 18
(8) H-Raster Center Adjustment ............................................................................................................. 18
(9) Mode 11 Pre-Adjustment................................................................................................................... 18
(10) White Balance Adjustment .............................................................................................................. 18
(A) Setting ............................................................................................................................................ 18
(B) Cut Off Adjustment......................................................................................................................... 19
(C) White Balance Adjustment (Factory Auto Adjustment) ................................................................. 19
(D) Maximum Brightness Adjustment .................................................................................................. 19
(11) Focus Adjustment............................................................................................................................ 19
(12) Convergence Adjust ........................................................................................................................ 19
(13) Power Saving Function Inspection.................................................................................................. 20
(14) Geometry Adjustment...................................................................................................................... 20
(15) DCC 1/2B Writing and Inspection ................................................................................................... 20
(16) Setting Before Shipment ................................................................................................................. 20
(17) Adjustment Magnetic Field.............................................................................................................. 20
(18) Timing Sheet ................................................................................................................................... 21
Reference
Distortion Adjustment............................................................................................................................ 25
Inspection of PnP communication and Writing EDID to EEPROM and inspection of
PnP communication................................................................... 28
16

N0501 Adjustment Specifications Ver. 1.1
2000,11,16
(1) Adjustment & Inspection Tools:
(A) Color Analyzer (B) Signal Generator CHAROMA 2135
(C) Multi Meter (D) Hi-Voltage Probe
(E) Convergence Meter (F) Demagnetizer
(G) Power Meter (H) Automatic Alignment System
(I) DDC write & inspection system
(2) TIMING TABLE(Factory Mode –20 MODES)
MODE RESOLUTION H-SYNC EREQ. V-SYNC FREQ H . POLARITY V . POLARITY
1 VGA350 31.5KHz 70Hz + -
2 VGA400 31.5kHz 70Hz - +
3 VGA480 31.5KHz 60Hz - -
4MAC
¢º
35K 35.0KHz 66Hz - -
5 800*600(56) 35.2KHz 56Hz + +
6 8514A 35.5KHz 87Hz + +
7 640*480(75) 37.5KHz 75Hz - -
8 EVGA400 37.8KHz 84Hz - +
9 800*600(60) 37.8KHz 60Hz + +
10 640*480 43.3KHz 85Hz - -
11 800*600(75) 46.8KHz 75Hz + +
12 1024*768(60) 48.3KHz 60Hz - -
13 MAC¢º 49K 49.7KHz 74Hz - -
14 800*600(85) 53.6KHz 85Hz + +
15 1024*768(70) 56.4KHz 70Hz - -
16 1024*768(75) 60.0KHz 75Hz + +
17 640*480(120) 63.7KHz 120Hz - -
18 1280*1024(60) 64.0KHz 60Hz + +
19 800*600(100) 64.0KHz 100Hz + +
20 1024*768(85) 68.6KHz 85Hz + +
(3) Definition for Normal Condition
(A) Input AC Voltage 110V/60HZ.
(B) Warm up time minimum 30 minutes.
(C) Crosshatch Reverse Pattern.
(D) ALL VR’s Adjust Center Position.
(E) Color temp 9300K
(F) OSD I-CON [R], [G], [B] gain control bar center position in Factory Mode
(4) Hot Key Operation
(A) Factory Mode: SELECT Key + UP (+) Key if pressed when the power SW on.
(B) OSD Position Control Mode: DOWN (-) Key if pressed when the power SW on.
17