Rolsen 25D26MA, 29D18MA, PF29D18MA, 29D99MA, 25D19MA Service Manual
...
FILE NO. SM-CTV-O-142
COLOR TELEVISION
SERVICE MANUAL
MODEL NO. 25D26MA/ 25D19MA/ PF25D19MA/
29D18MA/ PF29D18MA/ 29D99MA/
PF29D99MA/ 34D18MA/ PF34D8MA
CHASSIS NO. CH-10DR
Please read this manual carefully before service.
TABLE OF CONTENTS
SAFETY INSTRUCTIONS ........................................................................................1
ADJUSTMENTS .......................................................................................................4
SYSTEM BLOCK DIAGRAMS AND ICS...................................................................13
SERVICE DATA .......................................................................................................17
REPLACEMENT OF PARTS.....................................................................................50
APPENDIX 1. CIRCUIT DIAGRAMS
2. PRINTED CIRCUIT BOARD LAYOUTS
3. FINAL ASSEMBLY DIAGRAMS
4. FINAL WIRING DIAGRAMS
SERVICE MANUAL
SAFETY INSTRUCTIONS AND MAINTENANCE
WARNING: BEFORE SERVICING THIS CHASSIS, READ THE “X-RA Y RA DIATION PRECAUTION”,
“
SAFETY PRECAUTION”AND “PRODUCT SAFETY NOTICE”INSTRUCTIONS BELOW.
X-RAY RADIATION PRECAUTION
1. The EHT must be checked every time the TV is serviced to ensure that the CRT does not emit
X-ray radiation as result of excessive EHT voltage. The maximum EHT voltage permissible in any
operating circumstances must not exceed the rated value. When checking the EHT, use the High
Voltage Check procedure in this manual using an accurate EHT voltmeter.
2. The only source of X-RAY radiation in this TV is the CRT. The TV minimizes X-RAY radiation, which
ensures safety during normal operation. To prevent X-ray radiation, the replacement CRT must be
identical to the original fitted as specified in the parts list.
3. Some components used in this TV have safety related characteristics preventing the CRT from
emitting X-ray radiation. For continued safety, replacement component should be made after
referring the PRODUCT SAFETY NOTICE below.
4. Service and adjustment of the TV may result in changes in the nominal EHT voltage of the CRT
anode. So ensure that the maximum EHT voltage does not exceed the rated value after service
and adjustment.
SAFETY PRECAUTION
WARNING: REFER SERVICING TO QUALIFIED SERVICE PERSONNEL ONLY.
1. The TV has a nominal working EHT voltage. Extreme caution should be exercised when working
on the TV with the back removed.
1.1 Do not attempt to service this TV if you are not conversant with the precautions and procedures for
working on high voltage equipment.
1.2 When handling or working on the CRT, always discharge the anode to the TV chassis before
removing the anode cap in case of electric shock.
1.3 The CRT, if broken, will violently expel glass fragments. Use shatterproof goggles and take extreme
care while handling.
1.4 Do not hold the CRT by the neck as this is a very dangerous practice.
2. It is essential that to maintain the safety of the customer all power cord forms be replaced exactly
as supplied from factory.
3. Voltage exists between the hot and cold ground when the TV is in operation. Install a suitable
isolating transformer of beyond rated overall power when servicing or connecting any test
equipment for the sake of safety.
4. When replacing ICs, use specific tools or a static-proof electric iron with small power (below 35W).
5. Do not use a magnetized screwdriver when tightening or loosing the deflection yoke assembly to
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SERVICE MANUAL
avoid electronic gun magnetized and decrement in convergence of the CRT.
6. When remounting the TV chassis, ensure that all guard devices, such as nonmetal control buttons,
switch, insulating sleeve, shielding cover, isolating resistors and capacitors, are installed on the
original place.
7. Replace blown fuses within the TV with the fuse specified in the parts list.
8. When replacing wires or components to terminals or tags, wind the leads around the terminal
before soldering. When replacing safety components identified by the international hazard symbols
on the circuit diagram and parts list, it must be the company-approved type and must be mounted
as the original.
9. Keep wires away from high temperature components.
PRODUCT SAFETY NOTICE
CAUTION: FOR YOUR PROTECTION, THE FOLLOWING PRODUCT SAFETY NOTICE SHOULD BE
READ CAREFULLY BEFORE OPERATING AND SERVICING THIS TV SET.
1. Do not slap or beat the cabinet or CRT, since this may result in fire or explosion.
2. Never allow the TV sharing a plug or socket with other large-power equipment. Doing so may result
in too large load, thus causing fire.
3. Do not allow anything to rest on or roll over the power cord. Protect the power cord from being
walked on, modified, cut or pinched, particularly at plugs.
4. Do not place any objects, especially heavy objects and lightings, on top of the TV set. Do not install
the TV near any heat sources such as radiators, heat registers, stove, or other apparatus that
produce heat.
5. Service personnel should observe the SAFETY INSTRUCTIONS in this manual during use and
servicing of this TV set. Otherwise, the resulted damage is not protected by the manufacturer.
6. Many electrical and mechanical components in this chassis have special safety-related
characteristics. These characteristics are often passed unnoticed by a visual inspection and the
X-ray radiation protection afforded by them cannot necessarily be obtained by using replacements
rated at higher voltages or wattage, etc. Components which have these special safety
characteristics in this manual and its supplements are identified by the international hazard
symbols on the circuit diagram and parts list. Before replacing any of these components read the
parts list in this manual carefully. Substitute replacement components which do not have the same
safety characteristics as specified in the parts list may create X-ray radiation.
Safety Symbol Description
The lightning symbol in the triangle tells you that the voltage inside this product may be
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SERVICE MANUAL
strong enough to cause an electric shock. Extreme caution should be exercised when
working on the TV with the back removed.
This is an international hazard symbol, telling you that the components identified by the
symbol have special safety-related characteristics.
FDA This symbol tells you that the critical components identified by the FDA marking have
special safety-related characteristics.
UL This symbol tells you that the critical components identified by the UL marking have
special safety-related characteristics.
MAINTENANCE
1. Place the TV set on a stable stand or base that is of adequate size and strength to prevent it from
being accidentally tipped over, pushed off, or pulled off. Do not place the set near or over a
radiator or heat register, or where it is exposed to direct sunlight.
2. Do not install the TV set in a place exposed to rain, water, excessive dust, mechanical vibrations or
impacts.
3. Allow enough space (at least 10cm) between the TV and wall or enclosures for proper ventilation.
4. Slots and openings in the cabinet should never be blocked by clothes or other objects.
5. Please power off the TV set and disconnect it from the wall immediately if any abnormal condition
are met, such as bad smell, belching smoke, sparkling, abnormal sound or no picture/sound/raster.
Hold the plug firmly when disconnecting the power cord.
6. Unplug the TV set from the wall outlet before cleaning or polishing it. Use a dry soft cloth for
cleaning the exterior of the TV set or CRT screen. Do not use liquid cleaners or aerosol cleaners.
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SERVICE MANUAL
ADJUSTMENTS
Set-up Adjustments
The following adjustments should be made when a complete realignment is required or a new CRT
is installed. Perform the adjustments in order as follows.
1. Colour purity
2. Convergence
3. White Balance
Note:
The purity/convergence magnet assembly and rubber wedges need mechanical positioning. Refer to
Fig. 1, 2.
1. Colour Purity Adjustment
Note:
Before attempting any purity adjustment, the TV should be operated for at least 15 minutes.
1) Demagnetize the CRT and cabinet using a degaussing coil.
2) Set the brightness and contrast to maximum.
3) Receive the green raster pattern.
4) Loosen the clamp screw holding the deflection yoke and slide it backward or forward to display
vertical green belt (zone) on the screen.
5) Remove the rubber wedge.
6) Rotate and spread the tabs of the purity magnet around the neck of the CRT until the green belt is on
the center of the screen.
7) Slowly move the deflection yoke forward or backward until a uniform green screen is obtained.
Tighten the clamp screw of the yoke temporarily.
8) Check purity of the red and blue raster.
Glass Cloth Tapes
Purity/Convergence
Magnet Module
Deflection Yoke
Adhesive
Rubber
Deflection Yoke
Dummy Wedge
Fig. 1
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SERVICE MANUAL
Fig. 2
2. Convergence Adjustment
Note:
Before attempting any convergence adjustment, the TV should be operated for at least 15 minutes.
Center convergence adjustment
1) Receive the cross hatch pattern.
2) Set the brightness and contrast properly.
3) Adjust two tabs of the 4-pole magnet to change the angle between them and red and blue vertical
lines are superimposed on the center area of the screen.
4) Turn both tabs at the same time keeping the angle constant to superimpose red and blue horizontal
lines on the center of the screen.
5) Adjust two tabs of 6-pole magnet to superimpose red/blue line and green line. Adjusting the angle
affects the vertical lines and rotating both magnets affects the horizontal lines.
6) Repeat steps 3)～5) keeping in mind red, green and blue movement. 4-pole magnet and 6-pole
magnet interact each other, resulting in complicating and dot movement.
Circumference convergence adjustment
1) Loosen the clamping screw of the defection yoke slightly to allow it to tilt.
2) Temporarily put a wedge as shown in Fig.1.(Do not remove cover paper on adhesive part of the
wedge.)
3) Tilt front of the deflection yoke up or down to obtain better convergence in circumference.
Push the mounted wedge into the space between the CRT and yoke to fix the yoke temporarily.
4) Put other wedge into bottom space and remove the cover paper to stick.
5) Tilt front of the deflection yoke right or left to obtain better convergence in circumference.
6) Keep the deflection yoke position and put another wedge in either upper space. Remove cover
paper and stick the wedge on the CRT to fix the yoke.
7) Detach the temporarily mounted wedge and put it in another upper space. Stick it on the CRT
to fix the yoke.
8) After fixing three wedges, recheck overall convergence.
Tighten the screw firmly to fix the yoke and check if the yoke is fixed.
9) Stick three adhesive tapes on wedges as shown in Fig. 1.
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SERVICE MANUAL
BLU Red Red/BLU GRN
Red/BLU
GRN
BLU
Red
4-pole Magnet Movement 6-pole Magnet Movement
Center Convergence by Convergence Magnets
Incline the Yoke Up (or Down) Incline the Yoke Right (or Left)
Circumference Convergence by DEF Yoke
Fig. 3
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SERVICE MANUAL
Circuit Adjustments
1. General Description
All adjustments are thoroughly checked and corrected before the TV outgoing. Therefore the TV
should operate normally and deliver proper colour pictures upon installation. However, several minor
adjustments may be required depending on the particular location where the TV is operated.
This TV is shipped completely in carton. Carefully take out the TV from the carton and remove all
packing materials. Connect the power cord into a 220V AC, 50Hz two-pin power outlet. Turn on the
TV. Check and adjust all the customer controls such as brightness, contrast and colour to obtain
natural colour pictures.
2. Automatic Degaussing
A degaussing coil is mounted around the CRT so that external degaussing after moving the TV is
generally unnecessary, providing it is properly degaussed upon installation. The degaussing coil
operates in about 1 second after power on. If the set is moved or faced to a different direction, the
power switch must be switched off for at least 30 minutes in order that the automatic degaussing
circuit operates properly. Should the chassis or parts of the cabinet become magnetized to cause
poor colour purity, use an external-degaussing coil. Slowly move the degaussing coil around the
screen,the sides and front of the TV and slowly withdraw the coil to a distance of about 2m before
unplug it. If colour shading still exists, perform the Colour Purity Adjustment and Convergence
Adjustment procedures.
3. Supply Voltage Adjustment
Caution: +B voltage has close relation to high voltage. To avoid X-ray radiation, +B voltage should
be +135V.
1) Set AC power supply to 220±5V.
2) Connect a digital voltmeter to two pins of C878, and then turn on the TV.
3) Receive Philips pattern.
4) The voltmeter should read 135±0.5V (For BCK-46A, BCK46D and BCK24306L series switch
transformers) or 145±1V (For BCK50, BCK25405L and BCK24307L series switch transformers).
4. High Voltage Inspection
Caution: No high voltage adjustment should be done in the chassis.
1) Connect a precise high voltmeter to the second anode of the CRT.
2) Turn on the TV and set the brightness and contrast to minimum (i.e. set beam current of the CRT to
zero).
3) The high voltage tested should be 26.5±1KV (for 25”CRT) or 28.5±1KV (for 29”CRT) or 30.5KV±1KV
(for 34” CRT).
4) Set the brightness to minimum or maximum, and ensure high voltage not beyond limitation of 29 KV
(for 25”CRT) or 31KV (for 29”CRT) or 35KV (for 34” CRT) in any case.
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SERVICE MANUAL
5. Focus Adjustment
1) Use the remote control to set the contrast to maximum and the brightness, chroma to medium.
2) Set H. V. lines near center of Philips pattern to thinnest with the FCB on the FBT. After finishing
adjustment, ensure that no poor focusing exists near the center or around of the frame.
Before Adjusting After Adjusting
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SERVICE MANUAL
Service Mode and Bus Data
1. To enter the D/S (Design/Service) mode
a. To enter the USER SERVICE mode
Set the volume to 0. Then press and hold the MUTE button on the remote control， and press the
MENU button on the TV to enter the SERVICE mode. At this time, red “S” is displayed on the upper
center of the screen. Use the button on the remote control to turn off the TV. In this case， the
SERVICE mode is quitted.
b. To select the SERVICE menu
Press the CAL button on the remote control to highlight two preset menus and 7 menus related to
TDA884X and TDA9178 in turn.
c. To select and adjust data
Use the↓/↑buttons to highlight an adjustment and the ←/→ buttons to adjust. The adjusted data
are immediately output and stored in the EEPROM.
Warning!
The user service mode adjustment can be changed only when service personnel adjust the whole set
data during servicing. As the control data have dramatic effects on functions and performance of the TV,
service personnel should not tell user how to enter the SERVICE mode to avoid improper data settings.
2. OPTION menu
Table 1 Option Menu
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Item Description Bus Data
OPTION 1
AV AV terminals Please refer to settings of your TV.
SOUND
SYS
Sound system DK
PIM
Picture improvement IC TDA9178:
1-Yes，0-No
1
COMB
Comb filter TDA9181: 1-Yes，0-No
0
SOU IC
Sound processing IC TDA9859: 1-Yes，
0-No
1
POW SET 0
LANGSET0 Language option 1 RUS
LANGSET1 Language option 2 ENG
OPTION 2
WOOFER
Woofer: 1-Yes，0-No
0
AUT-SET
Auto test: 1-On，0-Off
1
R TIME Realtime clock setup 0
BRAND Brand 0
BLACK Black screen 1
AV.- T V 0
SERVICE MANUAL
3. ADJUST menu
Table 2 Adjustment Menu
Item Description Bus Data Remarks
MENU 1
AFW AFC bandwidth selection 0 For inspection only
IF-FREQ IF frequency 38 For inspection only
AFA Auto frequency tracing display IN For inspection only
AFB Auto frequency tracing display ABOVE For inspection only
AGC-TAK AGC control data 10 Adjustable
FIX AUD Fixed audio amplitude output 0
VOL_MIN Volume Min. 08 For inspection only
VOL_MID Volume Mid. 27 For inspection only
VOL_016 43 For inspection only
MENU 2
BRI-MAX Brightness Max. 63
BRI-MID Brightness Mid. 31
CON-MAX Contrast Max. 63
CON-MID Contrast Mid. 31
COL-MID Color Mid. 31
MENU 3
PAL NT S C
V-HALF Half vertical picture on/off 0
V-SLOPE Vertical shift 31 Set to optimum
V-AMPL Vertical amplitude 34 37 Set to optimum
S-CORR PAL vertical shift 26 Set to optimum
V-SHIFT PAL vertical shift 24 27 Set to optimum
V-ZOOM Vertical zoom 25 For inspection only
V-SCROLL Vertical captions mode-SCROLL 31 For inspection only
MENU 4
PAL NTSC Set to optimum
H-SHIFT Horizontal shift 24 46 Set to optimum
H-AMPL Horizontal amplitude 46 48 Set to optimum
H-PARAB Pincushion correction 26 Set to optimum
H-CORNER Quadrangle correction 38 Set to optimum
H-TRAP Trapezoidal correction 34 Set to optimum
MENU 5
R-DRV Red drive setup 31 For inspection only
G-DRV Green drive setup 31
B-DRV Blue drive setup 31
Y-DLY Brightness delay setup 8 For inspection only
(continued)
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SERVICE MANUAL
CL
Cathode voltage adjustment
（1-BMCC CRT）
5 For inspection only
AKB Auto dark balance adjusting switch 0 For inspection only
VSD Vertical output switch 0 For inspection only
MENU 6
CB Color band pass filter IF selection 0 For inspection only
CMB
Color sub-carrier output switch
Comb filter TD9181: 1-Yes，0-No
1
DS
Skin tone correction control: 1-On，
0-Off
1
DSA
Skin tone correction angle: 1-Skin
of eastern, 0-Skin of western
1
HCO Horizontal compensation 1 For inspection only
EVG Vertical output guard switch 0 For inspection only
MENU 7
CHROMA
DELAY
Brightness/color transient
improvement delay adjustment
3 For inspection only
BLACK
STRETC
Black level stretching adjustment 16 For inspection only
NONLINEARI Brightness linearity adjustment 32 For inspection only
VAR. GAMM Vertical non-linearity adjustment 32 For inspection only
PEAKING Peaking circuit 32 For inspection only
STEEPNESS Steepness control 48 For inspection only
CORING Coring circuit 32 For inspection only
LINE WIDTH Line width adjustment 10 For inspection only
MENU 8
ASK 1 For inspection only
DBL Blue level stretching 1 For inspection only
GBL 1 For inspection only
DGR 1 For inspection only
GGR 1 For inspection only
WGR 0 For inspection only
SGR 1 For inspection only
Notes:
① The data sheet may differ dependent on different models.
② The data sheet may differ dependent on different CRTs for the same model.
4. Service Mode Adjustment
1) Sub-brightness
a) Receive colour signals.
b) Set the contrast to maximum and brightness to medium.
c) Set the chroma to medium.
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SERVICE MANUAL
Enter the TV to the Service mode. Select “SUB-BRIGHT” by pressing the ←/→ buttons on the
remote control，and set the data to 31 by pressing the data adjustment buttons. Operate the TV for 5
minutes in the mode.
d) Adjust the sub-bright data until blurry picture does not appear on the high bright area of the screen
and too dim picture not on the low-bright area.
e) Set the contrast and brightness to maximum or minimum, and then test normal picture alternation.
f) If the picture does not become dark when the contrast and brightness are set to minimum, or not
become bright when set to maximum, then adjust the sub-bright data to get normal picture.
2) White balance adjustment
a) Turn on the TV and preheat it for over 7 minutes.
b) Use the remote control to set the contrast to maximum and the brightness to medium. Set the
chroma to minimum.
c) Enter the TV to the Service mode, and set the following data without changing other items.
R-DRIVE············70
G-DRIVE············15
B-DRIVE············70
d) Pull out the external antenna and press the MUTE button once on the remote control until a right
horizontal line appears on the screen. Adjust the R-DRV data to get 160V±0.5 green gun voltage
across the CRT RGB PCB.
e) Adjust the G-DRV and B-DRV data according to Step 4 so that the bright horizontal line turns to
yellow，then to white.
3) Horizontal centering adjustment
Enter the TV to the Service mode and receive Philips pattern. Select “H.PH/60H” by pressing the ←
/→ buttons on the remote control, and adjust horizontal picture position in the center of screen by
pressing the data adjustment buttons.
4) Vertical centering adjustment
Enter the TV to the Service mode and receive Philips pattern. Select “V.POS/60H” by pressing the
←/→ buttons on the remote control, and adjust vertical picture position in the center of screen by
pressing the data adjustment buttons.
5) Vertical amplitude adjustment
Enter the TV to the Service mode and receive cross hatch pattern. Select “V.SIZE/60H” by pressing
the ←/ → buttons on the remote control, and adjust vertical amplitude by pressing the data
adjustment buttons so that vertical amplitude is not enough. Continue to adjust vertical amplitude by
pressing the data adjustment button until the first bar on the cross hatch pattern touches edge of the
screen.
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SERVICE MANUAL
SYSTEM BLOCK DIAGRAMS AND KEY ICS
Block Diagram of Chassis
150-250V
50Hz
Fig. 4 Chassis Block Diagram
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SERVICE MANUAL
Block Diagram of Supply Voltage System
150-250V
50Hz
Fig. 5 Block Diagram of Supply Voltage System
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