Memorex MT2325 Schematic
MT2325
SER VICE MANUAL
COLOR TELEVISION RECEIVER
ORIGINAL
MFR’S VERSION A
Design and specifications are subject to change without notice.
SERVICING NOTICES ON CHECKING
As for the places which need special attentions,
they are indicated with the labels or seals on the
cabinet, chassis and parts. Make sure to keep the
indications and notices in the operation manual.
2. AVOID AN ELECTRIC SHOCK
There is a high voltage part inside. Avoid an
electric shock while the electric current is
flowing.
3. USE THE DESIGNATED PARTS
The parts in this equipment have the specific
characters of incombustibility and withstand
voltage for safety. Therefore, the part which is
replaced should be used the part which has
the same character.
Especially as to the important parts for safety
which is indicated in the circuit diagram or the
table of parts as a mark, the designated
parts must be used.
PUT PARTS AND WIRES IN THE
4.
ORIGINAL POSITION AFTER
ASSEMBLING OR WIRING
There are parts which use the insulation
material such as a tube or tape for safety, or
which are assembled in the condition that
these do not contact with the printed board.
The inside wiring is designed not to get closer
to the pyrogenic parts and high voltage parts.
Therefore, put these parts in the original
positions.
5. TAKE CARE TO DEAL WITH THE
CATHODE-RAY TUBE
In the condition that an explosion-proof cathoderay tube is set in this equipment, safety is
secured against implosion. However, when
removing it or serving from backward, it is
dangerous to give a shock. Take enough care to
deal with it.
6. AVOID AN X-RAY1. KEEP THE NOTICES
Safety is secured against an X-ray by considering about the cathode-ray tube and the high
voltage peripheral circuit, etc.
Therefore, when repairing the high voltage peripheral circuit, use the designated parts and
make sure not modify the circuit.
Repairing except indicates causes rising of high
voltage, and it emits an X-ray from the cathoderay tube.
7.PERFORM A SAFETY CHECK AFTER
SERVICING
Confirm that the screws, parts and wiring which
were removed in order to service are put in the
original positions, or whether there are the
portions which are deteriorated around the
serviced places serviced or not. Check the
insulation between the antenna terminal or
external metal and the AC cord plug blades.
And be sure the safety of that.
(INSULATION CHECK PROCEDURE)
1.
Unplug the plug from the AC outlet.
2.
Remove the antenna terminal on TV and turn
on the TV.
3.
Insulation resistance between the cord plug
terminals and the eternal exposure metal
[Note 2] should be more than 1M ohm by
using the 500V insulation resistance meter
[Note 1].
4.
If the insulation resistance is less than 1M
ohm, the inspection repair should be
required.
[Note 1]
If you have not the 500V insulation
resistance meter, use a Tester.
[Note 2]
External exposure metal: Antenna terminal
HOW TO ORDER PARTS
Please include the following informations when you order parts. (Particularly the VERSION LETTER.)
1. MODEL NUMBER and VERSION LETTER
The MODEL NUMBER can be found on the back of each product and the VERSION LETTER can be
found at the end of the SERIAL NUMBER.
2. PART NO. and DESCRIPTION
You can find it in your SERVICE MANUAL.
IMPORTANT
Inferior silicon grease can damage IC's and transistors.
When replacing an IC's or transistors, use only specified silicon grease (YG6260M).
Remove all old silicon before applying new silicon.
A1-1
CONTENTS
SERVICING NOTICES ON CHECKING ......................................................................................................
HOW TO ORDER PARTS............................................................................................................................
IMPORTANT ...............................................................................................................................................
CONTENTS .................................................................................................................................................
GENERAL SPECIFICATIONS.....................................................................................................................
DISASSEMBLY INSTRUCTIONS
1. REMOVAL OF ANODE CAP...............................................................................................................
SERVICE MODE LIST ................................................................................................................................
CONFIRMATION OF USING HOURS .........................................................................................................
NOTE FOR THE REPLACING OF MEMORY IC ........................................................................................
ELECTRICAL ADJUSTMENTS ...................................................................................................................
MAJOR COMPONENTS LOCATION GUIDE .............................................................................................
BLOCK DIAGRAM......................................................................................................................................
PRINTED CIRCUIT BOARDS
MAIN/CRT/COMB ..................................................................................................................................
SCHEMATIC DIAGRAMS
MICON/TUNER ......................................................................................................................................
CHROMA................................................................................................................................................
DEFLECTION/CRT ................................................................................................................................
TV POWER.............................................................................................................................................
SOUND ...................................................................................................................................................
JACK/SOUND.........................................................................................................................................
STEREO/MONO.....................................................................................................................................
COMB/FILTER .......................................................................................................................................
WAVEFORMS .............................................................................................................................................
MECHANICAL EXPLODED VIEW ..............................................................................................................
MECHANICAL REPLACEMENT PARTS LIST...........................................................................................
ELECTRICAL REPLACEMENT PARTS LIST ............................................................................................
A1-1
A1-1
A1-1
A2-1
A3-1~A3-4
B-1
C-1
C-1
C-1
D1-1~D2-1
D3-1
E-1, E-2
F-1~F-4
G-1, G-2
G-3, G-4
G-5, G-6
G-7, G-8
G-9, G-10
G-11, G-12
G-13, G-14
G-15, G-16
H-1, H-2
I-1, I-2
J1-1
J2-1, J2-2
A2-1
GENERAL SPECIFICATIONS
G-1.Outline of the Product
32 inch( 806.0 mmV):Measured diagonally
Color CRT 110 degree deflection
G-2.Broadcasting System
US System M
G-3.Color System NTSC PAL SECAM or Monochrome signal
G-4.NTSC Playback(PAL 60Hz) Yes No
G-5.NTSC 3.58+4.43/PAL60Hz Yes No
G-6.Antenna Input Impedance
VHF/UHF 75 ohm unbalanced
G-7.Tuner and Receiving Contactless Electric tuner 1Tuner System
2Tuner System
channel Tuner Oscar(W/O HYPER) Oscar(W/ HYPER)
France CATV) Others
Receiving channel
(USA) 2~ 69 , 4A , A-5~A-1, A~ I , J~ W , W+1~ W+84
(G) , , , , ,
(F:SECAM) , ,
(F:PAL) , , , , ,
(UK)
Tuning System
Frequency syn. Voltage syn. Others
G-8.Preset Channel
-- channels
G-9.Intermediate Frequency
Picture(fP) 45.75 MHz MHz MHz
Sound (fS) 41.25 MHz MHz MHz
fP-fS 4.50 MHz MHz MHz
G-10.Stereo/Dual TV Sound
Yes( NICAM GERMAN USA JAPAN) No
G-11. Tuner Sound Muting Yes No
G-12.Power Source 120 V AC 50Hz AC 60Hz
G-13.Power Consumption: 150 W at AC 120 V 60 Hz
(Approx) W at DC V
Stand by(Approx): 8 W at AC 120 V 60 Hz
Per Year: kWh / Year
G-14.Dimensions(Approx.)
766 mm(W) 566 mm(D) 745 mm(H)
G-15.Weight(Approx.) Net : 55 kg ( -- lbs)
Gross: 58 kg ( -- lbs)
G-16.Cabinet Material
Cabinet Front: PS 94HB DECABROM
AB S 94V2 NON-DECA
94V0
Back Panel: PS 94HB DECABROM
AB S 94V2 NON-DECA
94V0
A3- 1
GENERAL SPECIFICATIONS
G-17.Protector: Power Fuse
G-18.Regulation
S afety
UL CSA SAA SI CE SEV
BS NF NEMKO FEMKO DEMKO IEC65
SEMKO NZ HOMOLO SAB S CNS SISIR
NOM AS3159 DENTORI UNE GOST NONE
Radiation
FCC DOC FTZ PTT CE SEV
SABA SI NF NZ HOMOLO UNE
CNS CISPR13 DENTORI AS/NZS NONE
X-Radiation
PTB DHHS HWC DENTORI NONE
G-19.Temperature
Operation 5 ºC~ 40 ºC
Storage -20 ºC~ 60 ºC
G-20.Operating Humidity Less than 80 %RH
G-21.Clock and Timer
Sleep Timer Yes Max 120 Min.( 10 Min. Step) No
On/Off Timer Yes Programs No
Wake Up Timer Yes Programs No
G-22.Timer back up Time
More than -- Minutes (at Power Off Mode)
G-23.Terminals
G-24.Indicator
( ) ( ) ( )
G-25.Display
On Screen Display
VHF/UHF Antenna Din Typ e F-Type France Type
Video Input(Front) Phono Jack ( R CA ø8.3) BNC
Video Input(Rear) Phono Jack ( R CA ø8.3) BNC
Video Output(Rear) Phono Jack ( R CA ø8.3) BNC
Audio Input(Front) Phono Jack ( R CA ø8.3) x2
Audio Input(Rear) Phono Jack ( R CA ø8.3) x2
Audio Output(Rear) Phono Jack ( R CA ø8.3) x2
21 Pin (x ) DC Jack(Center +) Ear Phone Jack(ø3.5)
Head Phone Jack(ø3.5) AC Outlet Ext Speaker
Diversity S Input(Front) S Input(Rear)
Power Stand B y On Timer NONE
Menu Clock Set( 12H 24H) System Select On/Off Timer
Hotel Lock Area Code CH Tuning
Sound 1/2 NICAM Auto Off Picture
Guide CH Se t Audio Language
CATV Pin Code Registration V-Chip
Control Leve l Volume Brightness Contrast
Color Tint Sharpness
Tuning Bass Treble
Balance Back Light
Stereo, Audio Output, Bilingual Picture Menu
Stereo, Audio Output, S AP Mid Night Theater
Stereo, Audio Output GAME
AV Channel Clock Hotel Lock
Sleep Timer Sound Mute Pin Code
A3- 2
GENERAL SPECIFICATIONS
G-26.OSD Language
Eng Ger Fre Spa Ita Por Jpn
OSD Language Setting
Eng Ger Fre Spa Ita Por Jpn Not Applicable
G-27.Speaker : P o s i t i o n Front Side Bottom
Size 3 inches
Imp 8 ohm x 2 pcs
Power Max 3.5 + 3.5 W
10% 2.6 + 2.6 W (Typical)
Imp 4 ohm x 2 pcs (form OCT Order)
Power Max 5.0 + 5.0 W (form OCT Order)
10% 4.5 + 4.5 W (Typical) (form OCT Order)
P o s i t i o n Center
Size -- inches
Imp -- ohm x -- pcs
Power Max -- W
10% -- W (Typical)
G-28.EXT Speaker : Yes -- W Imp -- ohm
G-29.Carton : Master Carton: Need No Need
Content: ---- Set
Material: ---- / ---- Corrugated Carton
Dimensions: ---- mm(W) ---- mm(D) ---- mm(H)
Description of Origin Yes No
Gift Box : M aterial Double/Brown Corrugated Carton ( with Photo Label)
Double/White Corrugated Carton ( with Photo Label)
Double Full Color Carton W/Photo
Dimensions: 856 mm(W) 648 mm(D) 845 mm(H)
Design: As Per BUYER ' s
Description of Origin: Yes No
Drop Test Natural Dropping At 1 Corner / 3 Edges / 6 Surfaces
Height 25cm 31cm 46cm 62cm 80cm
Container Stuffing: 88 Sets / 40' container
G-30.Accessories
Owner's Manual ( W/Guarantee Card) [English/French]
AC Plug Adapter Channel Film
Battery (UM- x ) Remote Control Unit
S afety Tip Toll Free Insert Sheet
Guarantee Card Audio-Video Cord (R CA )
Registration Card Warning Sheet
Quick Set-Up Sheet Schematic Diagram
Information Sheet U/V Mi xe r
75 ohm Coaxial Cable ( Single Shield Double Shield)
300 ohm to 75 ohm VHF Antenna Adaptor
21pin Cable Car Cord
Rod Antenna
One Pole Two Pole ( F-Typ e Din Type France Typ e)
Loop Antenna ( F-Typ e Din Type France Typ e)
G-31.Other Features
Auto Degauss Auto Search Full OSD
Auto Shut Off CH Allocation Premiere
Canal+ SAP Comb Filter
CATV(181Ch) Channel Lock Auto CH Memory
Anti-Theft Just Clock Function Hotel Lock
Rental Game Position Fastext
Closed Caption Center Woofer
Picture Menu Mid Night Theater V-Chip
A3- 3
GENERAL SPECIFICATIONS
G-32.Switch
Front
Power(Tact) Channel Up/Reset Volume Up/Set Up
System Select Channel Down/Enter Volume Down/Set Down
Main Power SW Sub Power Menu:Vol Up + Vol Down
Rear
AC/DC TV/CATV Selector
Degauss Main Power SW
G-33.Magnetic Field
BV : +0.45G BV : +0.35G BV : +0.25G
BH : 0.18G BH : 0.30G BH : 0.30G
BV : -0.15G B V : -0.25G B V : -0.50G
BH : 0.15G B H : 0.15G B H : 0.30G
G-34.Remote Control Unit: RC-CS
Glow in Dark Remocon Yes No
Power Source: D.C 3 V Battery UM - 3 x 2
Total 42 Key
Power Quick View TV/AV
Stand B y Status Bar Select
0 Time Select PAL/SECAM
1 Time Se t Volume Up
2 Muting Volume Down
3 CH Skip CH Call
4 CH1/CH2 CH Down
5 Channel CH Up
6 Text/Mix/TV CH Down/Page Down
7 Display Cancel CH Up/Page Up
8 Initial P age +/ 9 Store Program
10 Reveal F/T/B
11 Sleep Hold
12 Aft/Skip List
0/10 Auto Memory Std/Auto
Tone 1/2 Auto Memory
Info Call Band Select
Mono/Auto Reset Search
TV/Caption/Text Menu Clock/Program
Expand Enter Clock/Set
Red Add Ch S et
Cyan Delete Set +
Normal Yellow Set Color System Random Green
Wide Selecy Tuning Up/Time T ext Nicam/Mono
Auto Wide On/Off Tuning Down/Reset Tone A/B
Picture Position Navi FM Transmitter
Direct Change/Auto Search Back Light
Picture Menu Mid Night Theater Audio Select
Multi Brand Key
VCR Power CH Enter TV
Cable Power Rec VCR
Pause/Still Stop Cable
TV/VCR(VCR) Rew Play
FF MBR Se t
Preset Rotate
5.5/6.5MHz Browse
A3- 4
DISASSEMBLY INSTRUCTIONS
1. REMOVAL OF ANODE CAP
Read the following NOTED items before starting work.
*
After turning the power off there might still be a potential
voltage that is very dangerous. When removing the
Anode Cap, make sure to discharge the Anode Cap's
potential voltage.
*
Do not use pliers to loosen or tighten the Anode Cap
terminal, this may cause the spring to be damaged.
REMOVAL
1. Follow the steps as follows to discharge the Anode Cap.
(Refer to Fig. 1-1.)
Connect one end of an Alligator Clip to the metal part of a
flat-blade screwdriver and the other end to ground.
While holding the plastic part of the insulated Screwdriver,
touch the support of the Anode with the tip of the
Screwdriver.
A cracking noise will be heard as the voltage is discharged.
GND on the CRT
3. After one side is removed, pull in the opposite direction to
remove the other.
NOTE
Take care not to damage the Rubber Cap.
INSTALLATION
1. Clean the spot where the cap was located with a small
amount of alcohol. (Refer to Fig. 1-3.)
Location of Anode Cap
Fig. 1-3
NOTE
Confirm that there is no dirt, dust, etc. at the spot where
the cap was located.
2.3.Arrange the wire of the Anode Cap and make sure the
wire is not twisted.
Turn over the Rubber Cap. (Refer to Fig. 1-4.)
Screwdriver
Alligator Clip
GND on the CRT
Flip up the sides of the Rubber Cap in the direction of the
2.
arrow and remove one side of the support.
(Refer to Fig. 1-2.)
Rubber Cap
CRT
Support
Support
CRT
Fig. 1-1
Fig. 1-2
Fig. 1-4
4. Insert one end of the Anode Support into the anode button,
then the other as shown in Fig. 1-5.
Support
CRT
5.6.Confirm that the Support is securely connected.
Put on the Rubber Cap without moving any parts.
Fig. 1-5
B-1
SERVICE MODE LIST
This unit provided with the following SERVICE MODES so you can repair, examine and adjust easily.
To enter the Service Mode, press both set key and remote control key for more than 2 seconds.
Set Key Remocon Key Operations
VOL. (-) MIN
0
Releasing of V-CHIP PASSWORD.
VOL. (-) MIN 1
VOL. (-) MIN 6
VOL. (-) MIN 8
VOL. (-) MIN
9
Initialization of the factory.
NOTE: Do not use this for the normal servicing.
POWER ON total hours is displayed on the screen.
Refer to the "CONFIRMATION OF USING HOURS".
Can be checked of the INITIAL DATA of MEMORY IC.
Refer to the "NOTE FOR THE REPLACING OF MEMORY IC".
Writing of EEPROM initial data.
NOTE: Do not use this for the normal servicing.
Display of the Adjustment MENU on the screen.
Refer to the "ELECTRICAL ADJUSTMENT" (On-Screen Display Adjustment).
CONFIRMATION OF USING HOURS
POWER ON total hours can be checked on the screen. Total hours are displayed in 16 system of notation.
1.
Set the VOLUME to minimum.
2.
Press both VOL. DOWN button on the set and Channel
button (6) on the remote control for more than 2 seconds.
3.
After the confirmation of using hours, turn off the power.
ADDRESS DATA
INIT 00 83
CRT ON
0010
FIG. 1
Initial setting content of MEMORY IC.
POWER ON total hours.
= (16 x 16 x 16 x thousands digit value)
+ (16 x 16 x hundreds digit value)
+ (16 x tens digit value)
+ (ones digit value)
NOTE FOR THE REPLACING OF MEMORY IC
If a service repair is undertaken where it has been required to change the MEMORY IC, the following steps should be taken to
ensure correct data settings while making reference to TABLE 1.
NOTE: No need the setting for after INI 9.
ADDRESS
DATA
1.
Enter DATA SET mode by setting VOLUME to minimum.
2.
Press both VOL. DOWN button on the set and Channel button (6) on the remote control for more than 2 seconds.
3.
ADDRESS and DATA should appear as FIG 1.
4.
ADDRESS is now selected and should "blink". Using the SET + or - keys on the remote, step through the ADDRESS until
required ADDRESS to be changed is reached.
5.
Press ENTER to select DATA. When DATA is selected, it will "blink".
6.
Again, step through the DATA using SET + or - until required DATA value has been selected.
7.
Pressing ENTER will take you back to ADDRESS for further selection if necessary.
8.
Repeat steps 4 to 7 until all data has been checked.
9.
When satisfied correct DATA has been entered, turn POWER off (return to STANDBY MODE) to finish DATA input.
The unit will now have the correct DATA for the new MEMORY IC.
INI00INI01INI02INI03INI04INI05INI06INI07INI08INI
09
8C 27 80 00 00 00 00 1B 07 04
Table 1
C-1
ELECTRICAL ADJUSTMENTS
1. BEFORE MAKING ELECTRICAL
ADJUSTMENTS
Read and perform these adjustments when repairing the
circuits or replacing electrical parts or PCB assemblies.
CAUTION
•
Use an isolation transformer when performing any
service on this chassis.
•
Before removing the anode cap, discharge electricity
because it contains high voltage.
•
When removing a PCB or related component, after
unfastening or changing a wire, be sure to put the wire
back in its original position.
Inferior silicon grease can damage IC's and transistors.
•
When replacing IC's and transistors, use only specified
silicon grease (YG6260M).
Remove all old silicon before applying new silicon.
1-1:Prepare the following measurement tools for
electrical adjustments.
1. Synchro Scope
2. Digital Voltmeter
2. BASIC ADJUSTMENTS
On-Screen Display Adjustment
In the condition of NO indication on the screen.
Press both VOL. DOWN button on the set and the
Channel button (9) on the remote control for more than
2 seconds to appear the adjustment mode on the
screen as shown in Fig. 2-1.
NOTE
Use the Channel buttons (1-8) on the remote control to
select the options shown in Fig. 2-1.
Press the Channel button (0) on the remote control to
end the adjustments.
1. H/V
2. AKB
3. COLOR TEMP
4. PICTURE
5. OTHERS
6. TEST PATTERN
7. STEREO/SAP
8. (VOL TEST) 0. END
Fig. 2-1
1. RF AGC DELAY
2. VIDEO LEVEL
3. FM LEVEL
4. OSD H
5. CUT OFF
6. X-RAY
7.
8. 0. RETURN
2-2: CUT OFF
1.
Place the set with Aging Test for more than 15 minutes.
2.
Using the remote control, set the brightness and
contrast to normal position.
3.
Activate the adjustment mode display of Fig. 2-1 and
press the channel button (5) on the remote control.
The Fig. 2-2 appears on the display.
4.
Press the channel button (5) on the remote control.
5.
Adjust the Screen Volume until a dim raster is obtained.
2-3: WHITE BALANCE
NOTE:
Adjust after performing adjustments in section 2-2.
1.
Place the set with Aging Test for more than 15 minutes.
2.
Receive the color bar pattern.
3.
Activate the adjustment mode display of Fig. 2-1 and
press the channel button (2) on the remote control.
The Fig. 2-3 appears on the display.
4.
Adjust the adjustment mode display of Fig. 2-3 until the
white color is looked like a white.
1. AKB AUTO
2. R. BIAS
3. G. BIAS
4. B. BIAS
5. R. DRIVE
6. G. DRIVE
7. B. DRIVE
8. AGC AUTO 0. RETURN
Fig. 2-2
Fig. 2-3
2-1: RF AGC DELAY
1.
Place the set with Aging Test for more than 15 minutes.
2.
Receive a 70dB monoscope pattern.
3.
Connect the digital voltmeter between the pin 2 of
CP101 and the pin 6 (GND) of CP101.
4.
Activate the adjustment mode display of Fig. 2-1 and
press the channel button (5) on the remote control.
The Fig. 2-2 appears on the display.
5.
Press the channel button (1) on the remote control.
6.
Press the VOL. UP/DOWN button on the remote control
until the digital voltmeter is 2.3 ± 0.05V.
D1-1
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