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SERVICE MANUAL

CM-336 CM-337
COLOR VIDEO MONITOR

M618

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.

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TABLE OF CONTENTS PAGE 3 4 4 4 5 5 6 7 8 8 8 8 9

1. 2.

SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRECAUTION AND NOTICES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-l 2-2 2-3 2-4 SAFETY PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . PRODUCT SAFETY NOTICE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SERVICE NOTES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . HIGH VOLTAGE WARNING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3. 4. 5.

OPERATING

TIMING DIAGRAM & TABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADJUSTMENT 5-l 5-2 5-3 5-4 ..................................................................

ADJUSTMENT CONDITIONS AND PRECAUTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . MAIN CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ADJUSTING THE FRONT CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ALIGNMENT PROCEDURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.

PCB L A Y O U T . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 6-l 6-2 MAIN PCB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VIDEO PCB LAYOUT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 15 16

7. 8.

BLOCK DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

TROUBLE SHOOTING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 B-l B-2 B-3 B-4 B-5 B-6 B-7 B-B NO RASTER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 ABNORMAL VIDEO ON CRT SCREEN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 ABNORMAL WHITE BALANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 NO BLANKING WORK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 H. OSC/DEF/HV CIRCUIT FAULT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 F/V CONVERTER AND ASSOCIATED CIRCUIT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 UNSTABLE SYNCHRONIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 POWER SUPPLY TROUBLE SHOOTING CHART . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 DISASSEMBLY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 25 26 40

9. 10. 11. 12.

MECHANICAL

LOCATION OF ADJUSTMENT VR (VARIABLE RESISTOR) OF P.C.B. . . . . . . . . . . . . . . . . . . PARTS LIST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . SCHEMATIC DIAGRAM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

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1. SPECIFICATIONS FOR CM-336/337 COLOR MONITOR 1. CRT: 14" (13V) Deflection, 29mm Neck, 0.28mm Dot Pitch, Non-Glare Screen Display Color: Unlimited Colors External Controls: Power On/Off, Contrast, Brightness, H-Center, H-Size, V-Center, V-Size Input Video Signal Model 1 Model 2 Model 3 Model 4 Model 5 Model 6 RGB Analog TTL Level Negative TTL Level Negative

2. 3. 4.

RGB Analog RGB Analog RGB Analog RGB Analog RGB Analog Horiz. Sync. TTL Level Positive Vert Sync. TTL Level Negative 5. Resolution Horizontal: 720(H) Vertical: 350(H) 6. 720(H) 400(H) 640(H) 480(H) 800(H) 600(H) 1024(H) 768(H) TTL Level Negative TTL Level Positive TTL Level Negative TTL Level Negative TTL Level Negative TTL Level Negative TTL Level Positive T T L Level Positive

1024(H) 768(H)

Display Size (H-size & V-size set to center position) Horizontal: Vertical: 247 3mm 187 3mm 247 3mm 187 3mm 247 3mm 187 3mm 245 3mm 190 3mm 250 ? 3mm 187 3mM 247 3mm 3mm 187

7.

Display Time H o r i z o n t a l : 25.42~s Vertical: 11.17mS 25.42~s 12.76mS 25.42r.l.S 15.25mS 22.22/._& 17.06mS 22.80/_& 10.80mS 15.75/.& 15.88mS

8.

Scanning Frequencies Horizontal: 29.5KHz - 50KHz (CM-3361 29.5KHz - 6OKHz (CM-3371 Vertical: 45Hz - 90Hz

9.

Misconvergence Center: Corner: 0.3mm Max. 0.5mm Max. 65MHz (-3dB) Switching Mode Power Supply AC 90 - 264V, 50/60Hz Universal 5" to 40C Ambient 20% to 85% Relative, Non-Condensing 12.3Kgs (Net), 14.3Kgs (Gross) 356(W) x 349(H) x 385(D) mm 455(W) x 450(H) x 460(D) mm 15 Pin D-type Connector

10. 11.

Video Bandwidth: Power Source:

12. 13. 14. 15.

Operating Temperature: Humidity: Weight: Dimensions Moni ter: Carton: External Connection:

16.

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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 shatter-proof 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 protection, 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 customer, a thorough safety test must be performed 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 screwheads. 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 voltameter having 5000 ohms per volt or with more sensitivity in the following
manner: Connect a 1500 ohms 10 Watt resistor, paralleled by a 0.1 Eimfd, 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 0.15mfd capacitor.

(c) Reverse the AC plug at the AC outlet and repeat AC voltage measurements for each exposed
metallic 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.

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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 10mm (l/2 in) away from circuit board. 3. 4. Keep wires away from high voltage or high temperature components. 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 equipment. 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 25KV+ IKV with a line voltage of 120V AC. Higher voltage may also increase possibility of failure in HV supply. It is important to maintain specified values of all components in the horizontal 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 between second anode lead and CRT dag grounding device. When servicing System, remove static charge from it by connecting a 10K ohm resistor in series wire (such as a test probe) between picture tube dag and 2nd anode lead. (AC nected from AC power outlet). meter connected the High Voltage with an insulated line cord discon-

The picture tube used in this monitor employs integral implosion protection. Replace with tube of the same type number for continued safety. Do not lift picture tube by the neck. Handle the picture tube only after discharging the high voltage completely. H.V. Protector. The high voltage adjustment control 2 (VR902) is permanently sealed at factory. Do not attempt to readjust.

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3. OPERATING INSTRUCTIONS This procedure gives you instructions for installing and using the CM-336/337 color display 1. Position the display on the desired operation and plug the power cord into a convenient AC outlet. Three-wire power cord must be shielded and is provided as a safety precaution as it connects the chassis and cabinet to theelectrical 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:

15 - Pin Color Display Signal Cable

PIN NO 1 2 3

DESCRIPTION RED GREEN BLUE

PIN NO. 9 10 11 12 13 14 15

DESCRIPTION N. 0. GND SYNC. GND N. 0. HORIZ. SYNC VERT. SYNC N. 0.

RED SHIELD GND GREEN SHIELD GND BLUE SHIELD GND

3.

Apply power to the display by turning the power switch to the "ON" position and allow about I.hirty seconds for display tube warmup. The Power-On indicator lights when the display is on. 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. If your CM-336/337 color display requires service, it must be returned with the power cord.

4.

5.

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4. TIMING DIAGRAM & TABLE
4-l TIMING DIAGRAM

H.SYNC _,

A = HORI. SYNC. PERIOD.
.I

Cl,.
<

A

B = HORI. ACTIVE TIME. C = HORI. SYNC. WIDTH. D= HORI. BACK PORCH.
E = VERT. SYNC. PERIOD.

V.VIDEO +IHl< F ,I

F = VERT. ACTIVE TIME. G = VERT. SYNC. WIDTH. H = VERT. BACK PORCH.

V.SYNC

4-2 TIMING TABLE MODE HORI. V.SYNC. POLARITY FREQUENCY 1.765 14.330 11.171 0.064 1.915 POSITIVE NEGATIVE 31.470KHz 1.765 14.330 12.766 0.064 1.117 NEGATIVE POSITIVE 31.470KHz 1.748 16.682 15.252 0.064 1.049 NEGATIVE NEGATIVE 31.470KHz 3.444 17.778 17.066 0.057 1.626 NEGATIVE NEGATIVE 35.156KHz 1.158 11.498 10.808 0.113 3.563 POSITIVE POSITIVE 35.528KHz 6 2.461 16.666 15.880 0.124 3.600 NEGATIVE NEGATIVE 48.363KHz 1.920 14.272 13.599 0.106 3.513 NEGATIVE NEGATIVE 56.476KHz

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