AOC CM-336 User manual

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
SPECIFICATIONS................................................................
3
PRECAUTION AND NOTICES ..................................................... 4
2-l SAFETY PRECAUTIONS ....................................................
4
2-2 PRODUCT SAFETY NOTICE ................................................
4
2-3 SERVICE NOTES. .........................................................
5
2-4 HIGH VOLTAGE WARNING ................................................
5
OPERATING INSTRUCTIONS .....................................................
6
TIMING DIAGRAM &TABLE .....................................................
7
ADJUSTMENT ..................................................................
8
5-l ADJUSTMENT CONDITIONS AND PRECAUTIONS .............................
8
5-2 MAIN CONTROLS.........................................................
8
5-3 ADJUSTING THE FRONT CONTROLS .......................................
8
5-4 ALIGNMENT PROCEDURE .................................................
9
PCB LAYOUT...................................................................
14
6-l MAIN PCB LAYOUT.......................................................
14
6-2 VIDEO PCB LAYOUT......................................................
15
BLOCK DIAGRAM...............................................................
16
TROUBLE SHOOTING...........................................................
18
B-l NO RASTER..............................................................
18
B-2 ABNORMAL VIDEO ON CRT SCREEN .......................................
19
B-3 ABNORMAL WHITE BALANCE ..............................................
19
B-4 NO BLANKING WORK ..................................................... 20
B-5 H.
OSC/DEF/HV CIRCUIT FAULT ........................................... 20
B-6 F/V CONVERTER AND ASSOCIATED CIRCUIT ...............................
21
B-7 UNSTABLE SYNCHRONIZATION ............................................
21
B-B POWER SUPPLY TROUBLE SHOOTING CHART ...............................
22
MECHANICAL DISASSEMBLY .................................................... 23
LOCATION OF ADJUSTMENT VR (VARIABLE RESISTOR) OF P.C.B. ..................
25
PARTS LIST....................................................................
26
SCHEMATIC DIAGRAM.......................................................... 40
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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
2.
Display Color:
Unlimited Colors
3.
External Controls:
Power On/Off, Contrast, Brightness, H-Center, H-Size, V-Center, V-Size
4.
Input Video Signal
Model 1 Model 2 Model 3 Model 4 Model 5
RGB Analog RGB Analog RGB Analog RGB Analog RGB Analog
Horiz. Sync. TTL Level TTL Level TTL Level TTL Level TTL Level
Positive Negative Negative Negative Positive
Vert Sync. TTL Level TTL Level TTL Level TTL Level TTL
Level
Negative Positive Negative Negative Positive
5.
Resolution
Horizontal: 720(H)
Vertical: 350(H)
6.
Display Size (H-size &V-size set to center position)
Horizontal: 247±3mm 247
± 3mm
247 ± 3mm 245
± 3mm 250 ±? 3mm
Vertical:
187 ± 3mm 187 ± 3mm
187 ± 3mm 190
± 3mm 187 ± 3mM
7.
Display Time
Horizontal
: 25.42~s
Vertical:
11.17mS
8.
Scanning Frequencies
Horizontal:
29.5KHz - 50KHz (CM-3361
29.5KHz - 6OKHz (CM-3371
Vertical: 45Hz
- 90Hz
9.
Misconvergence
Center: 0.3mm Max.
Corner: 0.5mm Max.
10.
Video Bandwidth:
11.
Power Source:
12.
13.
14.
15.
16.
Operating Temperature:
Humidity:
Weight:
Dimensions Moni ter:
Carton:
External Connection:
720(H) 640(H) 800(H) 1024(H) 1024(H)
400(H) 480(H) 600(H)
768(H)
768(H)
25.42~s 25.42r.l.S 22.22/._&
22.80/_& 15.75/.&
12.76mS 15.25mS 17.06mS 10.80mS 15.88mS
65MHz
(-3dB)
Switching Mode Power Supply
AC 90
- 264V, 50/60Hz Universal
5” to 40°C 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
Model 6
RGB Analog
TTL Level
Negative
TTL Level
Negative
247
± 3mm
187
± 3mm
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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 de-
signated 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)
(b)
(c)
(d)
Plug the AC line cord directly into rated AC outlet (do not use a line isolation transformer
during this check).
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.
Reverse the AC plug at the AC outlet and repeat AC voltage measurements for each exposed
metallic part.
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. Keep wires away from high voltage or high temperature 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 precau-
tions necessary when working on high voltage equipment.
Exercise care when servicing this chassis with power applied. Many B plus and high voltage ter-
minals 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 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 discon-
nected from AC power outlet).
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 DESCRIPTION PIN NO. DESCRIPTION
1 RED 9 N. 0.
2 GREEN 10 GND
3 BLUE 11 SYNC. GND
12 N. 0.
13 HORIZ. SYNC
RED SHIELD GND
14
VERT. SYNC
GREEN SHIELD GND 15 N. 0.
BLUE SHIELD GND
.hirty
3. Apply power to the display by turning the power switch to the “ON” position and allow about I
seconds for display tube warmup. 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 bright-
ness and contrast to the most pleasing display.
5. If your CM-336/337 color display requires service, it must be returned with the power cord.
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4. TIMING DIAGRAM & TABLE
4-l TIMING DIAGRAM
H.SYNC
_, Cl,.
A
<
.I
V.VIDEO
+IHl<
F
,I
V.SYNC
4-2 TIMING TABLE
MODE
6
1.765 14.330 11.171 0.064
1.765 14.330 12.766 0.064
1.748 16.682 15.252 0.064
3.444 17.778 17.066 0.057
1.158 11.498 10.808 0.113
2.461 16.666 15.880 0.124
1.920 14.272 13.599 0.106
A = HORI. SYNC. PERIOD.
B
= HORI. ACTIVE TIME.
C = HORI. SYNC. WIDTH.
D=
HORI. BACK PORCH.
E = VERT. SYNC. PERIOD.
F = VERT. ACTIVE TIME.
G = VERT. SYNC. WIDTH.
H
= VERT. BACK PORCH.
1.915 POSITIVE
1.117 NEGATIVE
1.049 NEGATIVE
1.626 NEGATIVE
3.563 POSITIVE
3.600 NEGATIVE
3.513 NEGATIVE
V.SYNC.
POLARITY
NEGATIVE
HORI.
FREQUENCY
31.470KHz
POSITIVE
31.470KHz
NEGATIVE
31.470KHz
NEGATIVE
35.156KHz
POSITIVE
35.528KHz
NEGATIVE 48.363KHz
NEGATIVE
56.476KHz
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