SHARP D356P, D356PA Service Manual

SERVICE MANUAL

COLOR MONITOR

SPECTRUM 4V SERIES

(D356P/PA)

41A50-087

THESE DOCUMENTS ARE FOR REPAIR SERVICE INFORMATION ONLY. EVERY REASONABLE EFFORT HAS BEEN MADE TO ENSURE THE ACCURACY OF THIS MANUAL; WE CANNOT GUARANTEE THE ACCURACY OF THIS INFORMATION AFTER THE DATE OF PUBLICATION AND DISCLAIMS LIABILITY FOR CHANGES, ERRORS OR OMISSIONS,

MANUFACTURE DATA : JUNE. 1999

TABLE OF CONTENTS

PAGE

1. SPECIFICATIONS ..................................................................................................... 2

2. PRECAUTION AND NOTICES ................................................................................ 3

2-1 SAFETY PRECAUTIONS .............................................................................. 3

2-2 PRODUCT SAFETY NOTICE ....................................................................... 3

2-3 SERVICE NOTES ........................................................................................... 4

2-4 HIGH VOLTAGE WARNING ....................................................................... 4

3. OPERATING INSTRUCTIONS ................................................................................ 5

4. ADJUSTMENT .......................................................................................................... 6

4-1 ADJUSTMENT CONDITIONS AND PRECAUTIONS ............................... 6

4-2 MAIN ADJUSTMENTS ................................................................................. 6

4-3 ADJUSTMENT METHOD ............................................................................. 6-7

5. CIRCUIT DESCRIPTION .......................................................................................... 8

6. TROUBLE SHOOTING CHART .............................................................................. 11

6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS .............................. 11-12

6-2 ABNORMAL DISPLAY ................................................................................. 13

6-3 NO BLANKING .............................................................................................. 14

6-4 HOR. /OSC /DEF /HV CIRCUIT FAULT ...................................................... 14

6-5 ABNORMAL HORIZONTAL DEFLECTION .............................................. 15

6-6 ABNORMAL VERTICAL SCANNING ........................................................ 16

6-7 SIDE-PIN CUSHION DISTORTION ............................................................. 17

6-8 POOR FOCUS ................................................................................................. 17

6-9 NO SOUND (FOR 4VA/4VnA/4VlrA ONLY)............................................... 23

6-10 POWER SUPPLY TROUBLE SHOOTING CHART .................................... 18

7. MECHANICAL OF CABINET FRONT DIS-ASSEMBLY...................................... 19

8. PARTS LISTING ....................................................................................................... 20

9. BLOCK DIAGRAM (DEFLECTION) ....................................................................... 36

9-1 BLOCK DIAGRAM (SMPS) ........................................................................ 37

10. IC BLOCK DIAGRAMS............................................................................................ 38

11. PCB LAYOUT ............................................................................................................ 41

12. SCHEMATIC DIAGRAM ......................................................................................... 43

1. SPECIFICATIONS FOR D356P COLOR MONITOR

1. CRT

35.5CM(14V) 90 Deflection, 29mm Neck, 0.28mm Dot Pitch, Non-Glare Screen

2. Viewable image Size: 33.5CM (13") diagonal

3. Display Color:Unlimited Colors

4. External Controls: Power On/Off, UP/Down key, Function key: Contrast, Brightness, H-Size, H-center, V-Size, V-Center, Pincushion, Trapezoid, volume (for 4VA/4VnA/4VlrA only)

5. Input Video Signal

Mode 1 Mode 2 Mode 3 Mode 4 Mode 5 Mode 6 Mode 7

RGB Analog RGB Analog RGB Analog RGB Analog RGB Analog RGB Analog RGB Analog

Horiz. Sync:

Vert. Sync:

TTL Level TTL Level TTL Level TTL Level TTL Leve l TTL Level TTL Leve l Negative Negative Negative Negative Positive Positive Negative TTL Level TTL Level TTL Level TTL Level TTL Leve l TTL Level TTL Leve l Positive Negative Negative Negative Positive Positive Negative

6. Resolution

Horizontal: Vertical : Fh (KHz): Fv (Hz) :

720 (H) 640 (H) 640 (H) 6 40 (H) 800 (H) 800 (H) 1024 (H) 400 (V) 480 (V) 480 (V) 4 80(V) 600(V) 600 (V) 768 (V)

31.5 31.5 37.5 43.3 46.8 53.7 48.4 70 60 75 85 75 85 60

7. Display Size Horizontal: 250 mm Vertical: 187 mm

8. Scanning Freq uencies Horizontal: Vertical:

30KHz ~ 54KHz 50 Hz ~ 120 Hz

9. Factory Preset Timings: 7 User Timings: 12

10. Misconvergence Center: 0.3 mm Max. Corner: 0.4 mm Max.

11. Video Bandwidth: 85 MHz

12. Power Source: Switching Mode Power Supply AC 100 ~240V, 50/60Hz Universal Type

13. Operating Temperature: 0 to 40 Ambient

14. Humidity: 10 to 85 Relative, Non-Condensing

Weight: 11Kgs(Net), 12.8Kgs(Gross)



16. Dimensions Monitor: Carton: 438(W) 394(H) 460(D)

Monitor:350(W) 352(H) 370(D)



17. External Connection: 15 Pin D-type Connector AC Power Cord

18. Speaker: (for 4VA/4VnA/4VlrA only) Rate power: 1W (per channel) Impedance:



19. Regulations: UL, CSA, DHHS, FCC-B, TÜV/GS, CE TÜV/MPR-II (for 4Vlr/4VlrA only)

2. PRECAUTIONS AND NOTICES

2-1 SAFETY PRECAUTIONS

1. Observe all caution and safety related notes located inside the display cabinet.

2. Operation of the display with the cover removed, may cause a serious shock hazard from the display power supply. Work on the display should not be attempted by anyone who is not thoroughly familiar with precautions necessary when working on high voltage equipment.

3. Do not install, remove or handle the picture tube in any manner unless shatterproof goggles are worn. People who are not so equipped should be kept away while handling picture tube. Keep picture tube away from the body while handling.

4. The picture tube is constructed to limit X-RAY radiation to 0.5 mR/HR. For continued p rotection, use the designated replacement tube only, and adjust the voltages so that the designated maximum rating at the anode will not be exceeded.

5. Before returning a serviced display to the c ustomer, a thorough sa fety test must be p erformed to verify that the display is safe to operate without danger or shock. Always perform an AC leakage current check on the exposed metallic parts of the cabinet, such as screw heads. Test method for current leakage is described as follow. (a) Plug the AC line cord directly into rated AC outlet (do not use a line isolation transformer during this

check).

(b) Use an AC voltmeter having 5000 ohms per volt or with more sensitivity in the following manner:

Connect a 1500 ohms 10 Watt resistor, paralleled by a 0.15UF, AC type capacitor between a known good earth ground (water pipe, conduit, etc.) and the exposed metallic parts simultaneously. Measure the AC voltage across the combination of 1500 ohms resistor and 0.15UF capacitor.

part.

(d) Voltage measured must not exceed 0.5 volts RMS. This corresponds to 0 .35 milliamp AC. Any value

exceeding this limit constitutes a potential shock hazard and must be corrected immediately.

2-2 PRODUCT SAFETY NOTICE

Many electrical and mechanical parts in this chassis have special safety visual inspections and the protection afforded by them cannot necessarily be obtained by using replacement components rated for higher voltage, wattage, etc. Before replacing any of these components read the parts list in this manual carefully. The use of substitute replacement parts which do not have the same safety characteristics as specified in the parts list may create shock, fire, X-RAY radiation or other hazards.

2-3 SERVICE NOTES

1. When replacing parts or circuit boards, clamp the lead wires around terminals before soldering.

2. When replacing a high wattage resistor (more than 1/2W of metal oxide film resistor) in circuit board, keep the resistor about 10 (1/2 in) away from circuit board.

3. Keep wires away from high voltage or high temp erature components.

4. Keep wires in their original position so as to reduce interference.

2-4 HIGH VOLTAGE WARNING

Operation of monitor outside of cabinet or with back removed may cause a serious shock hazard. Work on this model should only be performed by those who are thoroughly familiar with precautions necessary when working on high voltage equip ment. Exercise care when servicing this chassis with power applied. Many B plus and high voltage terminals are exposed which, if carelessly contacted, can cause serious shock or result in damage to the chassis. Maintain interconnecting ground lead connections between chassis and picture tube dag when operating chassis.

Certain HV failures can increase X-ray radiation. Monitor should not be operated with HV levels exceeding the specified rating for the chassis type. The maximum operating HV specified for the chassis used in this monitor is

24.5KV

With a line voltage of 120/240 VAC. Higher voltage may also increase possibility of failure in HV supply.

It is important to maintain specified values of all components in the hor izontal and high voltage circuits and anywhere else in the monitor that could cause a rise in high voltage or operating supply voltages. No changes should be made to the original design of the monitor. Components shown in the shaded areas on the schematic should be replaced with exact factory replacement parts. The use of unauthorized substitute parts may create a shock, fire or other hazard.

To determine the presence of high voltage, use an accurate, high impedance, HV meter connected between second anode lead and CRT dag grounding device. When servicing the High Voltage System, remove static charge from it by connecting a 10K ohm resistor in series with an insulated wire (such as a test probe) between picture tube dag and 2nd anode lead.(AC line cord disconnected from AC power outlet.)

The picture tube used in this monitor employs integral implosion protection. Replace with tube of the same type number for c ontinue safety. Do not lift picture t ube by t he neck. H andle the p icture t ube only a fter disc harging the high voltage completely.

1KV

3. OPERATING INSTRUCTIONS

This procedure gives you instructions for installing and using the 4V Series display.

1. Position the display on the desired operation and plug the power cord into a co nvenient AC outlet. Threewire power cord must be shielded and is provided as a safety precaution as it connects the chassis and cabinet to the electrical conduit ground. If the AC outlet in your location does not have provisions for the grounded type plug, the installer should attach the proper adapter to ensure a safe ground potential.

2. Connect the 15-pin color display shielded signal cable to your signal system device and lock both screws on the connector to ensure firm grounding. The connector information is as follow:

11 15

15 - Pin Color Display

Signal Cable

PIN NO. DESCRIPTION PIN NO. DESCRIPTION

1. RED 9. NC

2. GREEN 10. GND

3. BLUE 11. SYNC. GND

4. GND 12. SDA

5. GND 13. HORIZ. SYNC

6. GND-R 14.

VERT. SYNC (VCLK)

7. GND-G 15. SCL

8. GND-B

3. Apply power to the display by turning the power switch to the "ON" position and allow about thirty seconds for display tube warm-up. The Power-On indicator lights when the display is on.

4. With proper signals feed to the display, a pattern or data should appear on the screen, adjust the brightness and contrast to the most pleasing display.

5. This monitor has po wer sa vi ng func tio n fo llo wing t he V ESA DP MS . Be sure to co nnect t he s igna l cab le to the PC.

6. If your 4V Series color display requires service, it must be returned with the power cord.

4. ADJUSTMENT

4-1 ADJUSTMENT CONDITIONS AND PRECAUTIONS

1. Approximately 30 minutes should be allowed for warm up before proceeding.

2. Adjustments should be undertaken only on those necessary elements since most of them have been carefully preset at the factory.

4-2 MAIN ADJUSTMENTS

NO. FUNCTION LOCATION DESIGNATION

1. 15V ADJ PCB - MAIN VR901

2. B + ADJ PCB - MAIN VR902

3. R.B. DRIVE CRT - BOARD VR801,802

4. R.G.B. CUT-OFF CRT - BOARD VR803,804,805

5. ABL ADJ PCB - MAIN VR701

6. UP KEY PCB - MAIN SW101

7. DOWN KEY PCB - MAIN SW102

8. FUNCTION KEY PCB - MAIN SW103

4-3 ADJUSTMENT METHOD

1. 15V, B + & HV protection voltage adjustment:

A. Chroma-2000 Signal generator or PC equivalent, set mode 1( VGA 640480) pattern 1. B. Connect a DC voltage meter between TP 901 and ground, then adjust VR901 to be 15VDC.

C. Connect a DC voltage meter between TP 902 and ground, then adjust VR902 to be 90 VDC.

2. Factory preset timings adjustment:

A. When you turn on the monitor, the function LEDS will light up simultaneously for a while, then extinguish. B. You can press t he up/func two keys simul t aneously, the most left four LEDS will light up for a while then

extinguish.

C. Then you can select o ne of the eight functio ns including Contra st, Brightness, H-SI ZE, H-CENTER, V-

SIZE, V-CENT ER, Pi ncushion and Tr apezo id Simply pr ess the functio n key and the LE D will b e light up corresponding to the one selected, then press the up/down keys to get the factory presetting parameter value to your satisfaction.

D. Then you wil l pre ss the up/f unctio n two keys si multa neous ly again, the mo st right four LE DS wi ll ligh t up

for a while then extinguish, the factory preset timings adjustment is finished.

3. White balance and luminance adjustment:

A. Bias (low light) adjustment:

(a) Set mode 5 ( 800600 Fh: 46.8KHz ) full white pattern. (b) Adjust VR801, 802, 803, 804, 805, to make VR in the center position. (c) Warm up more th an 20 minute. (d) Brightness set to max. Contrast set to min. full white pattern, the n adjust FBT scr een VR to make Y=

1.0FL

(e) Brightness set to raster just cutoff, contrast set to 4FL, then adjust CRT board VR805 (B-Bias) VR803

(R-Bias) to make Y= 4

B. Gain (High light) adjustment:

(a) Set mode 5 ( 800600 Fh: 46.8KHz ) full white pattern. (b) Brightness set to raster just cutoff and set the contrast to max. (c) Adjust VR801, 802 to make color code x=281

C. Recheck item A&B to make sure both of them in spec.

0.2FL

0.2 FL, x= 281 ± 10, y= 311 ± 10

10, y=311 ± 10.

D. Full white luminance:

(a) Set mode 5 ( 800600 Fh: 46.8K ) full white pattern. (b) Image size : H:250

4mm, V:187±4mm.

(c) Brightness set to raster just cut off and set the contra st to max. (d) Adjust VR701 to make sure white luminance at 25 FL.

4. Focus adjustment:

A. Set mode 2 ( 640480 Fh: 31.5KHz ) with character full page. B. Adjust external brightness to raster cutoff and external contrast to max. , then adjust focus VR to make the

display be focused very well.

5. Purity adjustment

A. Be sure that the display is not being exposed to any external magnetic fields. B. Ensure that the spacing between the Purity, Convergence, Magnet, (PCM), assembly and the CRT stem is

29 .(See below diagram)

C. P roduce a complete, red pattern on the display. Adjust the purity magnet rings on the PCM assembly to

obtain a complete field of the color red. This is done by moving the two tabs in such a manner that they advance in an opposite direction but at the same time to obtain the same angle between the two tabs, which should be approximately 180.

D. Check the complete blue and co mplete green patterns to observe their r espective color purity. make mino r

adjustments if needed.

RELATIVE PLACEMENT OF TYPICAL COMPONENTS

Purity Magnets

6-pole Convergence Magnets

4-pole Convergence Magnets

Deflection Yoke

6. Convergence adjustment

A. Produce a magenta crosshatch on the display. B. Adjust the focus for the best overall focus on the display.

Also adjust the brightness to the desired condition.

C. Vertical red and blue lines are converged by varying the angle between the two tabs of the 4 pole magnets

on the PCM assembly. (See above diagrams)

D. Horizontal red and blue lines are converged by varying the two tabs together, keeping the angle between

them constant. E. Produce a white crosshatch pattern on the display. F. Vertical green and magenta lines are converged by varying the angle between the two tabs of the 6-pole

magnets. G. Horizontal green and magenta lines are converged by varying the two tabs together, keeping the angle

between them constant.

5. CIRCUIT DESCRIPTION

5-1 MICRO CIRCUIT

IC101 is CPU, This CPU has the following functions.

1. Detect timing mode by sensing the horizontal frequency, vertical frequency, the polarity of Hor. Sync and Ver. Sync.

2. Keyboard scan control.

3. Geometry and volume (4VA/4Vn A/4VlrA only) control internal D/A converters and I

4. Cs capacitor switch control.

5. Power saving control.

When CPU detects timing, it takes data fro m E volume (4VA/4VnA/4VlrA only) of this monitor. If key is pressed, the CPU will do some job according to the key function. For example, if function key is pressed, it can change different value to control screen geometry (H-SIZE, V-SIZE...etc.)

5-2 DEFLECTION CIRCUIT

Hor. sync. and Ver. sync. come from PC, go into the CPU (IC101). The output goes to the Hor. oscillation and Ver. oscillation processor (IC401). The IC401 treats sync. Signal and output the drive signal to horizontal and vertical

output circuit. IC401 also generates some functions for geometry use, like, horizontal center, vertical size, by I bus control, the geometry can be controlled. IC601 is a vertical output IC to supply the vertical scan. Q404, Q405, Q406 and L405 are the horizontal size controls. Q403 is the horizontal deflection output, supply the horizontal scan of the monitor. Q707 and Q601 generate the Blanking signal output to G1 of CRT. Q703 Q704 and Q705 are mute control, brightness control and G1 DC voltage output.

PROM (IC102), then output voltage to control the geometry and

C bus control.

5-3 VIDEO CIRCUIT

IC801 is a video amplifier, clamping signal input from pin No. 11 to restore the DC voltage of video signal, the signal output from IC801 pass through IC802 Video package amplifier stage LM2439, then go to the cut off DC restore stage, The video output signal is about 40Vpp.

5-4 POWER SUPP LY

The design uses a discontinuous flyback topology operating in current-mode resulting in a multiple output switcher with stack well. Faster diodes are used. The fast transient response of the control loop maintains picture integrity. Very fast current limiting protects the switcher agains short circ uit s. UC3842AM (IC901) is the current mode controller selected. It offers feed forward compensation, feedback error amplifier, and low voltage lock out features. The 3842 draws very little current is start up mode. There is enough power from the line bleeder to slowly charge a capacitor to the 16 volts needed to start the switcher. The FET starts a cycle by allowing current to flow into the primary of the power transformer. As current ramps up with time, the voltage across the current sense resistor (R929) also ramps to a point where the 3842 determines that enough power is stored and turns off the FET. As the voltage on the transformer reverses, power is dumped from the main power transformer through diodes into the different supplies. To keep RFI to a minimum and reduce transistor heating, a turn-off snubber network is placed across the FET. Current from the secondary windings are rectified and filtered to freate the desired voltages. Small high current capacitors quickly return charging current to the source. Filter inductors remove high frequency noise.

5-5 TRANSISTOR & DIODE CIRCUIT

LOCATION CIRCU IT FUNCTION DESCRIPTION

D901 ~ D904 Bridge Rectifier for AC Source D909 Half-Wave Rectifier for Start CKT D910 Clamp Diode for Snubber CKT D919 Rectifier for Output Voltage D921 Rectifier for Output Voltage D922 Rectifier for Output Voltage D923 Rectifier for Output Voltage D925 Rectifier for Output Voltage D927 Forward Bias when Q403 Turn-off to Protect B+ Block CKT D929 B+ Feed Back Rectifier from F.B.T Pulse Q904 Start CKT Amplifier Transistor Q907, Q908 Use for Off-Mode to Cut-off 6.3V Supply Voltage Q909, Q910 Use for Standy-By or Suspend Mode to Cut-off 15V Supply Voltage Q912, Q920 Push-Pull Topology to Drive Q911 Q401 Turn-on at Power ON/OFF and Change Mode to Protect Hor.Block Q402 HOR. Driver Transistor Q407, Q408 As a Switcher for H-Size Correction CKT Q410, Q426 H-Size Corection Mosfet (Q426 15" only) Q404, Q405 As Differential Amp. to Drive Q406 Q406 Darlington Transistor for H-Size Control Q703 As a Switcher to Mute Screen when Abnormal Qccurring Q704, Q705 Unit Brightness Control CKT Q601, Q707 Develop Blanking Signal Q813, Q814 A Amplifier to Corection and Support Clamp Signal

6-1 NO RASTER, CRT RELATIVE CIRCUIT PROBLEMS

90V, 12V CHECK MAIN PC BOARD

6.TROUBLE SHOOTING CHART

CHECK THE HIGE VOLTAGE OF CRT ABOUT 23.5 ~ 25KV

CHECK THE VOLTAGE OF CRT HEATER ABOUT 6.3V

CHECK SCREEN VOLTAGE ABOUT

400V TO 600V

BRIGHTNESS SET TO MAX. THEN CHECK CRT G1 VOLTAGE

LESS THAN 300V

CHECK POWER SAVING CIRCUIT, Q909, Q910

CHECK FAILSAFE CKT Q402, Q403 RELATIVE CKT.

CHECK CRT'S HEATER RELATIVE CIRCUIT Q907, Q908

CHECK FBT. D706, R723, C713

CHECK VOLTAGE OF THE CRT CATHODE ABOUT 60V TO 70V

CHECK BRIGHTNESS CIRCUIT Q703, Q704, Q705 RELATIVE CKT.

REFER ITEM 8-2 "ABNORMAL DISPLAY"

2.ABNORMAL VIDEO LEVEL ON SCREEN

CHECK THE VOLTAGE OF IC801 PIN 2, 16 ABOUT 8V

CHECK THE SIGNAL INPUT OF R.G.B. ABOUT 0.7Vpp

CHECK IC801 PIN 11 ABOUT 10Vpp

CHECK THE VIDEO OUTPUT OF IC801 PIN 13, 15, 18 ABOUT 3Vpp

R.G.B. APPROACH STANDARD

3. ABNORMAL DDC (PLUG & PLAY)

CHECK 8V RELATIVE CIRCUIT

CHECK SIGNAL CABLE OR INTERFACE CARD.

CHECK THE RELATIVE CIRCUIT OF Q813, Q814 OR CLAMP.

CHECK IC801, Q813, Q814

CHECK IC101 PIN 5 VOLTAGE ABOUT 5V

CHECK SIGNAL CABLE

CHECK IC102 GOOD OR FAIL

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