Page 1 MODELS JC-1531 VMA-2(H), (N), (NT), (T) JC-1531VMB-2 (H), (N), (NT), (T) JC-1531VMB-2(EE)(H), (EE)(N), (EE)(NT), (EE)(T) JC-1531 VMR-2(H), (N) MultiSync 4FGe COLOR MONITOR SERVICE MANUAL PART NO. 599910363 Better Service Better Reputation Better Profit SPECIFICATIONS - Electrical Description Pi c ture Tube 15”...
Page 2 The MultiSync 4FGe also supports multiple operating platforms including IBM compatible and Macintosh family systems. Increased resolution adds to the image clarity, and the MultiSync 4FGe monitor provides a wider range of higher resolution to meet your needs for now and in the future.
Page 3 Mechanical Description Molded plastic cabinet with tilt swivel base. 1. Cabinet Dimensions 372 (W) X 396 (H) X 414 (D) mm 372mm 3. Tilt Swivel Range 17.8 kg 4. Weight Power Switch 5. Controls Brightness Control Contrast Control Color Switch Sync Switch H Size Increase, H Size Decrease H Position Left, H Position right...
Page 4 Pin Assignment Table D-SUB INPUT MINI D-SUB 15P D-SUB 15P VGA, 8514/A & XGA Macintosh with Adapter Pin No. Mini D-Sub 15P D-SUB 15P GROUND GREEN BLUE H/V COMP SYNC GROUND GROUND SELF TEST GREEN. GROUND GROUND GROUND GROUND BLUE GROUND GROUND GROUND...
Page 5 Timing Charts Separate Sync Vertical Composite Sync Horizontal Vertical...
Page 7 THE METHOD FOR REMOVING THE TILT SWIVEL BASE Turn the monitor CRT face down as shown. (Top VIEW) Remove the screw “a” with washer, then remove the revolving stand from the display. Move the revolving stand so that the “FRONT’ mark is aligned with the cabinet side.
Page 8 DISASSEMBLY Cabinet Back Turn the monitor CRT face down as shown. (Top VIEW) Remove the three screws “b”. Cabinet Bottom Remove the CABINET BACK. Signal Cable Cabinet Front 3. Place the monitor on its base as shown. Remove the four screws “c” from the case, shielding (CRT), and remove the case, shielding (CRT).
Page 9 5. Disconnect the connectors “CN-J”, “CN-L”, “CN-C”, “CN-IN” and “CN-A”. (from VIDEO PWB ASSY) Disconnect the connectors “CN-B”, “CN-HC”, “CN-R”, “CN-G” and “CN- M”.(from CRT PWB ASSY) Remove the three screws “c”. Remove the screw “e”. Remove the VIDEO PWB ASSY. (with VIDEO BRACKET) Screw “c”...
Page 10 8. Turn the monitor CRT face down as shown. Remove the two screws “d”. Remove the Anode cap from CRT. Disconnect the CRT PWB ASSY. Disconnect the connectors “CN-E”, “CN-F”, “CN-VDY”, “CN-HDY” and “CN-K”. NOTE: Carefully discharge the CRT anode cap by shorting it to ground before removing the anode cap.
Page 11 CONTROL PWB ASSY Spindle Revolving Cabinet Bottom Power Line Filter Signal Cable SW REG UNIT DISASSEMBLY CN-Z CN-S Disconnect the connectors TN-K”, “CN-Z”, "CN-D/C"" and "CN-SW” Remove the two screws “e” and lift SW REG UNIT. Screw “e”...
Page 12 BOARD LAYOUT PARTS LOCATION- BOARD LAYOUT UNIT PWB ASSY UNIT PWB ASSY MAIN PWB ASSY VIDEO PWB ASSY (DISTORTION UNIT) (H OSC UNIT) -CRT PWB ASSY S W REG UNIT UNIT2 (HV PROTECTOR) (On the MAIN PWB ASSY) CONTROL L PWB ASSY BOARDS PWE-365 MAIN PWB ASSY...
Page 13 CONNECTORS CN-D -CN-E CN-V DY -CN-H DY CN-K -FBT MAIN PWB ASSY (PWE-365) CN-F CN-E CONTROL PWB ASSY (PWE-318)
Page 14 CN-J CN-C C N - A CN-L CN-I VIDEO PWB ASSY (PWE-315A) CN-G CN-R C N - B CN-HC CN-CE CN-M CRT PWB ASSY (PWE3158)
Page 15 SW REG PWB ASSY (VMA) CN-SW CN-Z CN-D/C CN-K SW REG PWB ASSY (VMB/R/B(EE))
Page 16 ADJUSTMENT CONTROLS LAYOUT UR854 (2.85V ADJ) VR851 (0.96V ADJ) TP AUTO VR852 (OV ADJ) UR403 (SIDEPIN) -TP-A VR503 (H SIZE) 0 VR401 ( V SuB HEIGHT) VR402 (V LINER) VR431 ( P A R A L L E L O ADJ) VR502(H HOLD 2) VR404 (TRAP...
Page 17 CN-TP VR710 (SUB BIAS) VR707 (R SUB BRIGHT) V R 7 0 5 B I A S ) / / VR706 (B BIAS) VR701 (R GAIN) VR702 (G GAIN) ---"-- : VR703 (B GAIN)/ V I D E O ASSY(PWE-315A) TP905 (GND) TP903 (B)
Page 18 ADJUSTSMENT PROCEDURE See page 26 for j i g Standard Adjustment Conditions 1) Power source voltage:JC-1531VMA-2 AC120V6OHz/JC-1531VMB-2,R-~, B-2(EE) AC220V50 power on for a minimum twenty minutes. 2) Aging :Ad_iust after leaving 3) Signal: Analog 0.7Vp-p 75Q terminal positive polarity Video Analog sync on green Video...
Page 19 See page 26 f o r j i g 2 . M a i n A d j u s t m e n t Service adjustment * Set the user switch positions as follows unless otherwise instructed. CONTRAST VR : F u l l y c l o c k w i s e BRIGHTNESS VR: Adjust to the point where the back raster just disappears F a r o n y o u r l e f t ( p o s i t i o n “N”)
Page 20 (2-l) MAIN PWB ADJUSTMENT Signal 1 (VGA350) Horizontal Hold Signal 10 (1024X768(76)) Receive signal lO(all "H"). Adjust VR852(5.14V ADJ) so that the voltage across TP43 and GND on Adjustment jig (TP-A @I and 0) is OV ±O.O5V. Short SW46 on Adjusting jig (TP-A @ and @> and adjust VR501 (H HOLD 1) so that there is one screen.
Page 21 Signal 6 (800x600(56)) (6) Parallelo 0 gram distortion (a) Receive a crosshatch pattern (with outside border). (b) Adjust the user control switches(SW107/108) to center the vertical screen position. (c) Adjust VR431 to center the horizontal position of the lower screen and the upper screen. (7) Trapezoid distortion Signal 6 (800X600(56)) (a) Receive a crosshatch pattern (with outside border).
Page 22 (10) Screen Position,Size,Side Pincushion,Digital control (10-l) Screen position and size Signal 1,2,3,4,5,6,7,8,9 * Independent adjustments of each signal (a) For signals 1 to 9(except signal 6), check that the screen position and size fall within the following limits. Screen Size Horizontal: 26Omm±2mm Vertical : 195mm±2mm Screen Position...
Page 23 (11) Video Amplitude * Check to make sure the video input signal is set at the following level. VIDEO : Analog 0.7Vp-p ±0.02V (75Q+lX terminal) (ll-1)Writing the Color Adjustment Reference Value signal 13 (VGA480 WINDOW) (a) Receive signal. (b) Short SW42 on Adjustment jig.(TP-A @ and 0) (c) Push MEMORY RECALL SWITCH(SW109) for at least 2 seconds.
Page 24 ( 1 2 ) C u t - o f f a d j u s t m e n t Signal 3 (VGA480) ( a ) lnit ial s e t t i n g s o f t h e a d j u s t m e n t VRs VR704-VR706 B I A S V R : F u l l y c o u n t e r c ockw i se...
Page 25 Signal 3 (VGA480) (14) SUB-BRIGHT Adjustment Signal 13 (VGA480 WINDOW) Short SW44 on Adjustment jig.(TP-B @ and @) Receive an ail-black signal of signal 3. Turn the brightness control fully clockwise. Adjust VR708 clockwise to obtain 6cd/d ±0.5 (using an analyzer). Receive the window pattern of signal 13.Set Y=Yl ±O.005 using VR709 Set X=X1 ±0.005 using VR707.
Page 26 S E T t h e u s e r s w i t c h (17) C O N T R A S T V R clockwise Fully B R I G H T N E S S V R F u l l y c l o c k w i s e COLOR SW L e f t m o s t p o s i t i o n ( p o s i t i o n "...
Page 27 Connect to TP-A on Connect to TP-B on MAIN PWB of 4FG and 4FCe. MAIN FWB of 4FG and 4FGe. TP-A TP-B This part is used SW46 (TP-A 89) sw44 ( TP43 for 4FG and 4FGe. (TP-A 8) SHORT ov a OPEN SW41 SW42...
Page 28 Purity Adjustment Be sure that the display is not being exposed to any external magnetic fields. Ensure that the spacing between the Purity Convergence Magnet (PCM) assembly and the CRT stem is 29 mm±1 mm. (See diagrams below) Produce a complete, red pattern on the screen. Adjust the purity magnet rings on the PCM assembly to obtain a complete field of the color red.
Page 33 ‘10 ‘07 ‘09 SVGA72 SVGA56 2 6 . 7 8 5 ; 2 8 . 6 3 9 ; 3 0 . 9 3 6 ; 24.304 32. 016 . i 3 1 . 9 6 0 i 6 0 . 9 8 0 1 27.004 56.
Page 34 WINDOW EVGA480 i 62kHz 3 1 . 9 5 2 f 2 8 . 3 2 0 i 3 1 . 4 9 6 i 3 0 . 7 5 2 1 4 2 . 4 8 9 ; 3 1 . 4 6 7 i 3 7 .
Page 35: Table Of Contents
CIRCUIT DESCRIPTION TABLE OF CONTENTS 1. , Power Supply Circuit ............................35 (l-l) SWITCHING REGULATOR UNIT ......................(a) Rectifying and filtering circuit ........................(b) Auxiliary power supply circuit ........................(c) Converter circuit ............................(d) Output rectifying circuit ..........................(e) Error detection amplifier circuit ......................... Oscillating and control circuit ........................
Page 36: Power Supply Circuit
CIRCUIT DESCRIPTION 1. Power Supply Circuit Dropper Circuit t +120V H D e f l e c t i o n +150V K1 D e f l e c t i o n F B T +8OV - 6 0 V High Voltage +24V DC/DC...
Page 37: (L-L) Switching Regulator Unit
l-1. Switching regulator unit (a) Rectifying and-filtering circuit AC input is rectified by D601. Then, it is filtered by C601. The resulting DC voltage is supplied to the ’ converter circuit. (Fig l-i -1) Rectifying and Filtering Circuit (b) Auxiliary power supply circuit The auxiliary power supply circuit is needed to activate IC601.
Page 38: (C) Converter Circuit
(c) Converter circuit converter circuit consists of the primary winding of the switching transformer T601, switching device Q601, and surge absorbers (C602, R602, C609, R620, D606, and D611) that are connected to the primary winding. The oscillating signal-from IC601 pin @ is applied to the gate of Q601 causing the drain-source to be turned OFF and ON so that the oscillating voltage is applied to the primary winding of T601.
Page 39: (E) Error Detection Amplifier Circuit
Error detection amplifier circuit The output voltage 80V is divided by the network resistors. This divided voltage is compared to the reference voltage at the error amplifier lC651. An error signal is applied to the control circuit via the photocoupler PC601. R655 C653 R654...
Page 40: (G) Overvoltage Protection
Overvoltage Protection If a failure occurs and the output voltage on the secondary winding rises, the voltages of the auxiliary winding will also rise proportionally. When the auxiliary windings voltage rises beyond the zener voltage of ZD604, CR602 will turn ON. This in turn will decrease the voltages at pinaof IC601 causing the oscillator within IC601 to stop.
Page 41: (1-Z) Hv Voltage Circuit
1-2. H V Voltage Circuit H V generator circuit (Fig 1-2-l) H V generator circuit is composed on Q515, C530, C531, and FBT T503. This circuit generates the flyback pulse. This pulse level is 450-55OVp-p. This flyback pulse is boosted up to the high voltage (24 KV) by FBT. The High voltage is supplied to the anode of CRT from FBT.
Page 45: (L-3) Dc/Dc Converter For H Deflection Circuit
1-3. DC/DC converter for H deflection circuit This circuit supplies DC voltages to H deflection circuit and controls H size and side-pin cushion correction by this output voltage. This DC/DC converter circuit is composed of a step down chopper circuit type, FET drive circuit and control circuit. This chopper circuit is composed of Q510, L504, L505, D508, C521, and C522.
Page 48: (L-4) Low Voltage Chopper Regulator Circuit
1-4. Low voltage chopper regulator circuit The low voltage chopper regulator circuit id PWM controlled and synchronized with the H deflection DC/DC converter output of the DC/DC converter. The pulse duty is determined by comparing the saw tooth waveform and the feedback voltage through error amp of IC5A4 with a comparator of IC5A3.
Page 50: Interface Circuit
2. Interface Circuit 2-1. Sync Interface Circuit (a) The outputs of this circuit are the positive H Sync and V Sync. The following three signals are designed as input signals. SEPARATE SYNC POSITIVE/NEGATIVE polarity (ii) COMPOSITE SYNC POSITIVE/NEGATIVE polarity (iii) SYNC ON GREEN NEGATIVE polarity S Y N C O N “...
Page 51: Sync Switch And Video Clamp Pulse Circuit
2-2. SYNC SW and Video Clamp Pulse Circuit The clamp pulse for IC702 (PRE-AMP) is generated at pin 0 of lC801. In case of the separate H sync and Comp sync, the clamp pulse is triggered by the front edge of .H sync and the pulse width is determined by C805 and R809.
Page 52: Self Test Circuit
2-3. Self Test Circuit When the signal cable is disconnected from the video card/computer, pin @ of CN-IN and pin @ of IC851 (CPU) are set High. Then H sync (pin a), V sync (pin @) and video (pin 0) compose the CPU generated self test pattern.
Page 53: Video System
3. Video System Video signal amplifier 3-1. The three video circuits are the same for the each R/G/B color. Threfore only the Green video circuit will be explained here. The Green video signal input is fed to the pin @of IC701 through the Q701G. The video signal is attenuated by IC701 ,and the attenuation level is controlled by the user contrast control.
Page 54: Brightness And Cut-Off Circuit
3-2. Brightness and cut-off circuit The raster brightness level is determined by clamping the video output blanking level from IC703. The DC clamp level is determined by using the voltage drop of R780G (which is basically determined by the current of Q78lG). The raster brightness level is determied by the voltage at ihe output of lC704-3.
Page 55: Video Mute And Video Blanking Circuit
3-3. Video Blanking Circuit and Video Mute Circuit The H blanking pulse is applied to the push pull circuit which is composed of Cl771 and Q772. During the blanking period this pulse turn on the transistor Ql and the video amplifier at cut-off. The video mute signal is generated at the CPU (pin @I), when input signal is changed.
Page 56: Digital Control System
4. Digital Control System 4-1. Digital Control Circuit The following items are controlled by the Digital Control System. Digital Control System Automatic Signal Identification Automatic Sizing Automatic Centering Memory of Picture Data The relationship of the input and the output of CPU (IC851) is shown on Fig. 4-l-l Converter Single Chip...
Page 60: Deflection System
5. Deflection System 5-l-l. Horizontal synchronization circuit AFC and Horizontal Oscillation are conduced by inputting Sync signal, Horizontal Output pulse and Horizontal Oscillation Control current to IC5Al (iA7850). The output of horizontal phase circuit is input to which is determined by R5A7 and R5A6. Horizontal Output pulse is input to IC5Al ( pin @) and the Saw Tooth Wave is generated at IC5Al ( pin 0).
Page 61: (5-L -2) H Phase Circuit
5-l-2. Horizontal phase circuit ADJUST CIRCUIT USER H POS CONTROL (Fig 5-l-2) BLOCK DIAGRAM of the H phase circuit Horizontal Position is to be adjusted by delaying the Horizontal Sync signal phase input to LA7850. IC5A6’s inputs of H position control voltage and saw tooth waveform are generated from the H sync timing. The duty comparator’s output varies with the H position control voltage.
Page 62: (5-L -3) H Drive Circuit
5-1-3. H DRIVE Circuit The horizontal pre-drive pulse is generated from IC5Al (LA7850) pin @ and input to Q503 via Q501 and power loss. Q504’s collector voltage is controlled by both H F/V and H size voltage. The relationship of Q504 collector voltage, H FN voltage and H size voltage is shown Fig 5-l -6.
Page 63: 5-L-4. H Output Circuit
The signal from T501 turns on and off the horizontal output transistor Q505. Consequently, Q505 is turned alternately on and off so that the SAW TOOTH current flows into the horizontal deflection yoke. The H band signals from IC851 input to GATE of Q506, Q507 and Q508 via PWE-366A. Consequently “S” capacitors frequency is higher than 40.5kHz, L501 is shorted by RL501.
Page 64 0507 H FREQUENCY GATE GATE GATE 52 kHz to 62 kHz 42 kHz to 46 kHz 37 kHz to 42 kHz 34 kHz to 37 kHz 32 kHz to 34 kHz 30 kHz to 32 kHz 27 kHz to 30 kHz (Fig 5-l-8) The relationship of H frequency, Signals from PWE-366A and "S"...
Page 65: (5-L -5) Parabola Waveform Generating Circuit
5-1-5. Parabola Waveform Generating Circuit The parabola-waveform generating circuit is mainly composed of two blocks (See Fig 5-1-l 0 and Fig 5-l-11)1 Each block includes a multiplier which has two input terminal. In the first block, a parabolic waveform is generated from the saw tooth wave.

This manual is also suitable for:

Jc-1531 vma-2 Jc-1531 vmb-2 Jc-1531 vmr-2

NEC MultiSync 4FGe Service Manual

1 Power Supply Circuit

2 Interface Circuit

3 Video System

4 Digital Control System

5 Deflection System

Quick Links

Summary of Contents for NEC MultiSync 4FGe

Page 35: Table Of Contents

Page 36: Power Supply Circuit

Page 37: (L-L) Switching Regulator Unit

Page 38: (C) Converter Circuit

Page 39: (E) Error Detection Amplifier Circuit

Page 40: (G) Overvoltage Protection

Page 41: (1-Z) Hv Voltage Circuit

Page 45: (L-3) Dc/Dc Converter For H Deflection Circuit

Page 48: (L-4) Low Voltage Chopper Regulator Circuit

Page 50: Interface Circuit

Page 51: Sync Switch And Video Clamp Pulse Circuit

Page 52: Self Test Circuit

Page 53: Video System

Page 54: Brightness And Cut-Off Circuit

Page 55: Video Mute And Video Blanking Circuit

Page 56: Digital Control System

Page 60: Deflection System

Page 61: (5-L -2) H Phase Circuit

Page 62: (5-L -3) H Drive Circuit

Page 63: 5-L-4. H Output Circuit

Page 65: (5-L -5) Parabola Waveform Generating Circuit

This manual is also suitable for:

NEC MultiSync 4FGe Service Manual

1 Power Supply Circuit

2 Interface Circuit

3 Video System

4 Digital Control System

5 Deflection System

Quick Links

Related Manuals for NEC MultiSync 4FGe

Summary of Contents for NEC MultiSync 4FGe

This manual is also suitable for:

Table of Contents