NEC MultiSync 2A Service Manual

Color monitor

Advertisement

Quick Links

NEC
coLoR MONITOR
SERVICE MANUAL
A.
Electrical Description
Picture Tube
13 Visual inches diagonal
90 degree deflection, 0.31 mm Trio dot pitch
Dot type black matrix
Non-long persistence phosphor, Dark bulb,
Direct etch
Input Signal
Video :ANALOG 0.7 or 1.0 Vp-pfi50 Positive
Sync. :Separate sync. TTL Level
Horizontal sync. Positive/Negative
Vertical sync. Positive/Negative
Display Colors
Analog Input
Synchronization
Horizontal
Vertical
Resolution
Horizontal
Vertical
MultiSync®2A
SPECIFICATIONS
:Unlimited colors
:31.SkHz and 35kHz (Auto­
matically)
:56Hz/60Hzfi0Hz (AutomRtically),
:800
Non interlace
:600
dots
lines
NEC Corporation
MODEL JC-1403HMA
Better Service
Better Reputation
Better Profit
·
�-
:··:·::
• ·
..
-�
.t
.
..
.
'
'
.
.
,.
"'
.
'
'
't
. •
<"
,
.
.
.
.
.
.
.
.
.
38MHz
Video Band Width
Active Display
Horizontal
Area
Vertical
Misconvergence
Less than 0.6mm
Power Supply
AC 120V, 60Hz
Power Consumption
90W
Environmental
Operating
Consideration
Storage
NOTE:
The above specifications are subject to change without notice
for further improvement.
t
f
I
.
.
.
.
.
#
,
.
.
r
f
{
p
•.
.
.
.
..
"
.
.
.
'
.
.
,
..
.
.
:240mm
Active display area is
:180mm
changed by signal timing
0°C to +40°C
Temperature
Humidity
30%to 80%
Temperature
-20°C to +60°C
Humidity
10%to90%

Advertisement

Table of Contents
loading

Summary of Contents for NEC MultiSync 2A

  • Page 1 Display Colors Analog Input :Unlimited colors Synchronization Horizontal :31.SkHz and 35kHz (Auto­ NOTE: matically) Vertical :56Hz/60Hzfi0Hz (AutomRtically), The above specifications are subject to change without notice :800 Non interlace for further improvement. :600 Resolution Horizontal dots Vertical lines NEC Corporation...
  • Page 2: Serial Numbers

    This Service Manual is applied only to those sets with serial numbers shown bel ow. LABEL SERIAL NUMBER Model No. Manufactured JC-1403HMA Serial No. D E C EM B ER 1988 8ZK00001S QC MARK "S" MANUFACTURED DATA CODE USE THE LAST NUMBER OF THE YEAR MANUFACTURED DATA CODE JAN TO SEP ..
  • Page 3 B. Mechanical Description (See below diagrams) Cabinet: Molded plastic cabinet with attachabl e till swivel Dimensions: base. 355(W) X 363(H) X406(D) mm Front Side "' <D "' 230mm 230mm 355mm 406 mm 3. Tilt Swivel Range 4. Weight: 11.7 kg 5.
  • Page 4 56Hz, 60Hz and 70Hz. As you can see, "design" was the top priority with the MultiSync 2A. With the intelligence to support the hardware timings of IBM's VGA and MCGA, the MultiSync 2A was also designed to be compatible with many non-IB M graphics boards supporting the Super VGA resolution of 800 X 600.
  • Page 5: Pin Assignments And Signal Levels

    PIN ASSIGNMENTS AND SIGNAL LEVELS Type 15-P Mini 0-SUB PIN NO. S IGNAL P IN NO. S IGNAL GROUND NO-CONNECT ION GREEN BLUE H. SYNC GROUND V. SYNC GROUND NO-CONNECT ION GROUND GROUND GROUND NO-CONNECTION GROUND TIMING CHARTS VIDEO HORIZONTAL SYNC VIDEO VERTICAL...
  • Page 6: Adjusting The Front Controls

    ADJUSTING THE FRONT CONTROLS V. POSITION C ONTROL OWER SWITCH ev.s1z BRIGHT NESS CONTROL E CONTROL CONTRAST CONTROL H. POSITION CONTROL ON/OFF (Power Switch) Used to turn the power ON or OFF. When the power is ON, the LED power indicator, located on the f ront of the monitor, is lit.
  • Page 8 DISASSEMBLY Turn the m o n itor set upside d own as shown. Screw " " Remove three screws 1 "a" from the cabinet bottom. Screw " " 3. Invert the monitor set as nor­ mal, then remove the cabinet back.
  • Page 9 4. Remove the three screws "b" and the two band. Remove a screw "c" and nut. Remove a screw "d". Anode Cap CRT PWB Band "b" Screw "d" Screw "c" and Screw Pawl SUB PWB 5. Remove the connecter "DY", "Z", "SW", "CN-D3", "CN-D5", and CRT Anode cap.
  • Page 10: Crt Pwb Assy

    SUB PWB UNIT DIS ASSEMBLY Remove the connecter "CN-S1" Remove the two screw "b" and the two band. Remove the two screw "e" and lift up the SUB PWB ASSY. BAND Screw " e " Screw "b" '---. r- - - - - - - - - - - ..., PWB UNIT DIS ASSEMBLY Remove the connecter "CN-C1'', "CN-C2", "CN-C3", "CN-C4"...
  • Page 11: Parts Location Diagrams

    PARTS LOCATION DIAGRAMS BOARDS PWE-242 MAIN PWB ASSY SUB PWB ASSY PWE-243A CRT PWB ASSY PWE-2438 VR PWB ASSY PWE-243C LED PWB ASSY PWE-243 0 - 9-...
  • Page 12 F.B.T VR451 V. L IN CN-D7 VR452 V. SUB HE IGHT CN-D6 VR554 H. PHASE (3) (MAC VR7A2 BRIGHTNESS VR552 H. PHASE (1) (VGA) 1 CONTRAST VR553 H. PHASE (2) 1800X600l VR5A1 H. POSITION VR551 H. F/V ADJ VR4A 1 V. SIZE VR556 H.
  • Page 13 CRT SOCKET VR706 B.BIAS TP703 VR 7 07 R. SUB. BRIGHT VR701 R. GAIN VR702 G. GA IN VR708 G. SUB. BRIGHT VR703 B. GAIN VR709 B. SUB. BRIGHT VR710 SUB. CONT TP701 TP702 VR704 R. B IAS CRT PWB ASSY (PWE-243B) VR705 G.
  • Page 14: Adjustment Procedure

    A DJUSTMENT PROCE DURE Standard Adjustment Conditions Power source voltage: AC120V 60 Hz Aging; Adjust after leaving power on for 20 minutes or more. Signals: Video: VGA, 800X600 mode, 0.7Vp-p 750 terminal, positive polarity mode Video: 0.7Vp-p sync.: 0.3Vp-p (750 terminal) Synchronizing: VGA, 800X600 mode TTL level positive polarity/negative polarity Separate Deflection frequency: H.
  • Page 15 Main Adjustment Set the external VRs as follows unless otherwise specified. Front controls VR7A1 CONTRAST: Max. (fully clockwise) VR7A2 BRIGHTNESS: At point where bac k raster disappears. VR4A2 V. POSITION: Mechanical center Center click position VR4A1 V. SIZE: VR5A1 H. POSITION: Center click position 3-1) MAIN PWB Adjustment (1) ±12V Adjustment...
  • Page 16 (6) Vertical Sub Height Receiving all white signal, adjust VR452 so that vertical screen size is 180 mm. (7) Side Pin Cushion Adjust VR401 for the optimum side pin cushion distortion. (8) Horizontal Width (when receiving all white signal) a) Receiving signal 4 (MAC11), adjust L504 (H. WIDTH COIL) so that horizontal width is 235 mm. b) Receiving signal 1 (VGA), adjust L503 (H.
  • Page 17 (3) Cut-off Adjustment (0.08Vp-p all white signal) a) Contrast Control Fully clockwise Brightness control Fully counterclockwise b) Short TP451 and TP551 at 12 k0 Turn the screen VR clockwise a little by little until a single color appears horizontally. Adjust the screen VR so that the color can faintly be seen.
  • Page 18 Purity Magnets Convergence) 4-pole magnets (Red Blue Convergence) 6-pole magnets (Green to Magenta 29.±1 Purity, Convergence Magnet Assembly (PCM) B/RG er orm t e a 1ustment y opening 1· � · the angle between the tabs. Perform the adjustment by opening �...
  • Page 19 TIMING OF REFERENCE SIGNALS BY LVG 1600 Indication Abbreviation Unit Signal 1 Signal 2 Signal 3 Signal 4 Signal 5 address address VGA 350 VGA 400 VGA 480 800X600 CLOCK 28.324 F 28.324F 28.324 F 30.246 F 36.000F H FREQ 31.470 F 31.470 F 31.470 F...
  • Page 20 DATA FO R MAT FOR USING Quantum 801C TIMING PARAMETERS: Signal No. Rear Time Parameters Description 31.47KHz 70Hz (350 Lines) Dot Rate 31.47KHz 70Hz (400 Lines) Horizontal Rate Vertical Rate 31.47KHz 60Hz (480 Lines) 35 OOKHz 67Hz H: 35.16KHz 56Hz Non-Real Time Parameters Horizontal Vertical...
  • Page 21 TEST SIGNALS FOR USING QUANTUM Real Ti me Parameters Dot Rate (MHz) 28.320 28.320 28.320 30.246 36.000 Horizontal Rate (kHz) 31.470 3 1 .470 31.470 35.000 35.160 Vertical Rate (Hz) 70.000 70.000 59.943 66.667 56.000 Non-Real Time Parameters H: Dots/Character Total 1 00 Characters...
  • Page 22: Troubleshooting

    TROUBLE SHOOTING BE FORE USING THIS CHART, PLEASE RE FER TO THE TROUBLE SHOOTING OF THE USER'S MANUAL. 1. NO RASTER CHECK 110V LINE MEASURE THE VOLTAGE BETWEEN CND7-GND CHECK 24V LINE AND CND6-GND ON THE MAIN PWB PWE-242 CHECK SW REG REEFER TO ITE M 13 CIRCUIT CHECK HV...
  • Page 23 2. ABNORMAL VIDEO ON CRT SCREEN TOO BRIGHT TOO DARK CHECK R,G,B VIDEO OUTPUT MEASURE THE VOL TAG ES POINTS TP701 , TP702, TP703 ON THE CRT PWB PWE-243B CHECK G1 VOLTAGE 1 00V LINE MEASURE THE VOLTAGE BETWEEN C5-1 AND C5-8 1 00V REG CIRCUITRY CONNECTOR D2-C5 BLANKING CIRCUITRY...
  • Page 24 3. ABNORMAL WHITE BALANCE AND TRACKING ABNORMAL BRIGHTNESS CONTROL 0701, 0702, 0703 IC701 FAILURE ABNORMAL CONTRAST CONTROL 0706, IC701 FAILURE READJUST WHITE BALANCE REFER TO THE ALIGNMENT PROCEDURE NO BLANKING WORKS VISIBLE RETRACE LINE ON THE BACK RASTER CHECK BLANKING CIRCUT ZD401 D406 D407...
  • Page 25 5. H. OSC/DEF/HV. CIRCUIT FAULT NO RASTER ABNORMAL PICTURE SIZE ABNORMAL VIDEO ON THE CRT SCREEN CHECK THE VOLTAGE FORM TWO VOLTAGE FORM SYNCHRON�ZING OF S2-3 AND S2-5 FREE RUNNING OR NO PULSE CHECK THE VOLTAGE CHECK THE VOLTAGE OF 0502 BASE FORM TP501 NO PULSE IC553, IC554 FAILURE...
  • Page 26 6. H-F/V CONVERTER AN D ASSOCIATE D CIRCUITRY CHECK H. SYNC CHECK THE POINT S2-3 FAILURE CHECK TP502 VOLTAGE MEASURE THE VOLT AGE ON THE SUB PWB PWE-243A SIGNAL CONDITION: SEE ALIGNMENT PROCEDURE READJUST IC 551, C554, C555 FAILURE CHECK THE IC552 MEASURE THE VOLTAGES OUTPUT ON THE SUB PWB PWE-24...
  • Page 27 LACK OF STABLE SYNCHRONIZATION • HORIZONTAL CHECK THE VOLTAGE FORM CHECK H.SYNC. O F CONNECTOR 04-3 SEE H- F/V CONVERTER CIRCU IT ITE M 6 CHECK H.SYNC CIRCUIT ON THE CRT PW8 PWE-2438 • VERTICAL CHECK V.SYNC CHECK THE VOLTAGE FOR M O F CONNECTOR 04-4 CHECK V.SYNC CIRCUIT ON THE CRT PW8 PWE-2438...
  • Page 28: Picture Size

    PICTURE SIZE ABNORMAL HORIZONTAL WIDTH 800X600 MODE ONLY OR 800X600 MODE AND VGA MODE ONLY FAULT VGA MODE FAULT READJUST L504 CHECK RL501 OPERATION AT 800X600 MODE D510, D512, 0508, 0509 0511 FAILURE READJUST L503 READJUST L503 AT VGA MODE AND L504 L503 FAILURE CHECK THE H.
  • Page 29: Picture Centering

    CENTERING • HORIZONTAL a) BACK RASTER CENTERING CHECK BACK RASTER CENTERING C IRCU IT R50 9 T502 (F. B. T) D502 D503 C512 CONNECTOR RH FAILURE b) PICTURE CENTERING READJUST SUB H CENTERING SEE AL IGNMENT PROCE DURE CHECK H.PHASE SHIFT C IRCU ITRY •...
  • Page 30 10. SIDE PINCUSHION DISTORTION FAILURE CHECK AT VGA 350 LINE OR 400 LINE MODE READJUST VR401 AT VGA 350 LINE MODE SIDE PINCUSHION DISTORTION CIRCUITRY FAILURE CHECK AT VGA 480 LINE MODE FAILURE CHECK AT 800X600 MODE 04 04 FAILURE -28 -...
  • Page 31 1 1. POOR FOCUS READJUST FOCUS CONTROL FOCUS CONTROL UNIT (T502:F.B.T) FAILURE 12. IMPURITY ON CRT SCREEN POWER SW O FF AND WAIT FOR 5-10 MINUTES TO ALLOW TH601 TO COOL OFF POWER SW ON AND PRODUCE VIDEO ON THE CRT CONFIRM DEGAUSSING EFFECT NO E F FECT E F FECT BUT...
  • Page 32 SWITCHING REGULATOR CIRCUIT TURN OFF POWER SW ITCH. AFTER ONE M INUTE, D ISCONNECT CN- D6 AND CN- D7, THEN TURN ON POWER SW ITCH. MEASURE VOLTAGE ACROSS C656 (+110V OUTPUT) AND ACROSS C660 (+24V OUTPUT) RESPECT IVELY WITH A D IGITAL MULTIMETER (DMM). APPROX.
  • Page 33: Circuit Description

    CIRCUIT DESCRIPTION 1. Video System 1- 1 Video amplifier circuit The analog video RGB signals are input from pins 1, 2 and 3 of 0-SUB 15-pin connector, and they are controlled by voltages at pins 1, 4, 8, 12 and 14 of CN-C1 connector. The video gain is adjusted with VR701 to VR703 so that 40Vp-p is obtained with Contrast Control in MAX position, or 10Vp-p in MIN position when 0.7Vp-p is input.
  • Page 34 Blanking circuit The blanking circuit eliminates horizontal and vertical retrace lines by lowering G1 voltage at the fly-back time. 1-7 100V regulation circuit The 1 OOV regulation circuit regulates DC11 OV, which is generated from the switching power supply, to 100V and it supplies 100V to the video output amplifier. 2.
  • Page 35 2-2-3 H. POSITION control circuit Horizontal display position is adjusted by shifting horizontal sync. signal to be input. Horizontal sync. signal is input to IC553 pin 1 1 . The shift time is determined by the time constant of CR to be connected to pin 1 4.
  • Page 36 3-3 Vercial centering Vertical centering is controlled by superimposing DC current onto the deflection yoke current. 3-4 Side pin compensating circuit The parabolic wave current generated at the V. DY is superimposed onto the horizontal deflecting current at T401. The amount of compensation is changed over according to the mode. SW, REG Sections &...
  • Page 37 4-2 Auxlllary power supply circuit Auxiliary powe r supply circuit is to activate IC602. At the time of power on, charging current fl ows into the capacito rs C6 1 5 and C624 via ZD601 and R605. Osci l l ation starts when the vo ltage of IC602 pin 16 reaches 1 7V through this charging o peration.
  • Page 38 Output smoothing circuit The fly-bac k voltage generated at the secondary winding of switching transformer T601 is rectified by D651 and D652. Then, it is smoothed by C651, C652 and C 658 so that DC current is obtained. This fly-bac k voltage is maintained constant by controlling the ON duty of 0601 in the converter circuit.
  • Page 39 4-6 Oaclllatlng circuit, control circuit and drive circuit The osc i l lati n g , contro l , and d rive ci rcui ts comp rise mai n ly IC602. The IC602 has a bui lt-i n osc i l lator of which frequency is determi n ed by R61 4, C61 3 a n d R61 3 co n n ected to p i ns 1 0 an d 1 1 respect ively.
  • Page 40: Replacement Parts List

    & R E P LAC E M E N T PA RTS L I ST Note: The components i d e n t i fied by m a r k a re c r i t i c a l for safety. Rep lace o n l y with parts N u m be r spec 1 f 1 e d .
  • Page 42 S Y M B O L P A R T S N O D E S C R I P T I ON S Y M B O L P A R T S N O D E S C R I P T I O N �...
  • Page 43 2SA934 2SA952 2SC2688 2SA733 2SC945 2SC2002 AA1A4M AA1 L4M A N 1 A4M 2SC38 1 1 2SD381 DTC1 1 4WS 2S D401 2S K762 2S K854 CRT PWB ASSY ( PWE-243 8) NOTE : -So l d e r s i d e- E: E M ITTER B : BASE C : COLLECTOR...
  • Page 44 PR I N T E D W I R I N G BOA R D S CN - $2 -& "' � E� � C565 ��I R5 2 1 !=�_o tr."' --+I- - QSOSE "'O - J- , "s 2 3, &_ J.JI .J.J2 e:..
  • Page 47 Este manual original foi gentilmente cedido para ser digitalizado por PY2TKI Marcos Digitalizado em 24 de Novembro de 2020 por Alexandre "Tabajara" Souza, PU2SEX http://www.tabalabs.com.br http://tabajara-labs.blogspot.com MANUAL DE DISTRIBUIÇÃO GRATUITA - Respeite o meu esforço de preservar a documentacao...
  • Page 48 S E R . N O . 209 1 7 .958901...

This manual is also suitable for:

Jc-1403hma

Table of Contents