Daewoo DR-C912B User manual

S/M No. : VCR9ADPEN0
✔ Caution :
In this Manual, some parts can be changed for improving, their perfor-
mance without notice in the parts list. So, if you need the latest parts
information,please refer to PPL(Parts Price List) in Service Information
Center (http://svc.dwe.co.kr).
DAEWOO ELECTRONICS Corp.
Jan., 2004
http : //svc.dwe.co.kr
Service Manual
DVD COMBO RECEIVER
MODEL : DR-C912B/913B
DR-C922B/923B
LR
VCR/REC DVD/P.SCAN VCR DVD AM/FM CH/PRESET+
REC P.SCAN SOUND FIELD CH/PRESET—
MIN MAX
PHONES
LR
VIDEO/REC
REW
TUNING
SEARCH
FF
DVD/P-SCAN VCR DVD AM/FM CH/PRESET+
REC P.SCAN SOUND FIELD CH/PRESET—
MIN MAX
PHONES

CONTENTS
Page
Number
SPECIFICATIONS.....................................................................1
CLEANING AND LUBRICATION...........................................1
TEST EQUIPMENT REQUIREMENTS ...................................2
THE SERVICE FIXTURE .........................................................2
PATH FIXTURE CONNECTION/
TEST POINT IDENTIFICATION ........................................3
LEADLESS (CHIP) COMPONENT
REMOVAL INSTRUCTION................................................3
LEADLESS (CHIP) COMPONENT INDENTIFICATION ......5
ABBREVIATIONS.....................................................................6
INSTRUMENT DISASSEMBLY ..............................................8
DESCRIPTION OF THE MECHANISM ................................12
ASSEMBLY DIAGRAM AND A/S ......................................14
DISASSEMBLY AND REPLACEMENT ..............................20
MECHANICAL ADJUSTMENT ............................................26
ADJUSTMENT OF THE TAPE TRANSPORT SECTION ....29
EXPLODED VIEW .................................................................35
ELECTRICAL ADJUSTMENT...............................................40
WAVEFORMS .........................................................................42
VOLTAGE CHARTS
SERVO/SYSCON/TIMER MI-COM.......................................46
IC EEPROM/SYNC SRPA/RESET/TR ..................................47
IC DRIVER/SWITCH .............................................................48
VIDEO(LUMA/CHROMA) AND LINEAR AUDIO..............49
VIDEO SWITCHING IC VOLTAGE CHARTS .....................50
HIFI AUDIO IC........................................................................51
AUDIO SWITCHING IC .........................................................51
TMI ...........................................................................................52
IC CODEC CS4228 .................................................................52
AMP MI-COM..........................................................................53
AMP DDX-8000 ......................................................................55
AMP DDX-2100 ......................................................................61
IC SMPS/FET/PHOTO COUPLER/REGULATOR/TR..........70
TROUBLESHOOTING GUIDES
POWER CIRCUIT....................................................................72
SYSTEM CIRCUIT..................................................................73
VIDEO CIRCUIT ....................................................................78
AUDIO CIRCUIT.....................................................................82
SCHEMATIC
POWER SUPPLY SCHEMATIC DIAGRAM............................ 98
SERVO & SYSCON SCHEMATIC DIAGRAM
(DVD COMBO RECEIVER) .......................................................99
VIDEO/AUDIO SCHEMATIC DIAGRAM
(DVD COMBO RECEIVER) ............................................100
Hi-Fi & S/W & PIF & MPX SCHEMATIC DIAGRAM
(DVD COMBO RECEIVER) .........................................................101
DIGITAL AUDIO/VIDEO SCHEMATIC DIAGRAM
(DVD COMBO RECEIVER) .....................................................102
RECEIVER FRONT PART SCHEMATIC DIAGRAM............103
DIGITAL AMP SCHEMATIC DIAGRAM .............................104
DVD SCHEMATIC DIAGRAM...............................................105
BLOCK DIAGRAM
RECEIVER SERVO & SYSCON BLOCK DIAGRAM ................110
COMBO RECEIVER VIDEO BLOCK DIAGRAM .......................111
NORMAL AUDIO BLOCK DIAGRAM..........................................112
Hi-Fi &SW & PIF BLOCK DIAGRAM...........................................113
DIGITAL AUDIO BLOCK DIAGRAM ...........................................114
AMP BLOCK DIAGRAM..................................................................115
CIRCUIT BOARD INDEX
MAIN PCB ...........................................................................................116
POWER/LOGIC PCB.................................................................117
AMP PCB..............................................................................................118
ELECTRICAL PARTLIST..............................................................119

1
SPECIFICATIONS
Cleaning and Lubrication
A. Cleaning the Tape Transport System
The following parts should be cleaned after every 500 hours
of use.
• TENSION POLE
• S-GUIDE POST
• FE HEAD
• S GUIDE ROLLER
• S-SLANT POLE
• VIDEO HEAD/DRUM
• T-SLANT POLE
• T-GUIDE ROLLER
• AC HEAD/AE HEAD
• T-GUIDE POST
• CAPSTAN SHAFT
• PINCH ROLLER
Note: After cleaning with alcohol, allow the parts to dry thor-
oughly before using a cassette tape.
B. Cleaning the Drive System
The following parts should be cleaned after every 500 hours
of use.
• REEL TABLE
• T MAIN BRAKE
• S MAIN BRAKE
• T MAIN BRAKE
• CAPSTAN FLYWHEEL/PULLEY
• REEL PULLEY
C. Lubrication points
The following parts should be cleaned and lubricated after
every 500 hours of use. Apply one (1) or two (2) drops of oil.
Refer to the "Replacement Parts List" for the stock number of
the recommended oil.
• S REEL TABLE POST
• T REEL TABLE POST
• IDLER PULLEY
Power Input :120 Volts AC 60Hz audio Input : -8.8dBm
Power Consumption :95Watts Audio output (common
Operating Temperature :5 degree C to 35 degree C use of DVD and VCR) : Audio output terminal (2 kinds):
( 41 degree F to 95 degree F) -8.8dBm(VCR), 2.0Vrms(DVD)
Storage Temperature : -30 degree C to 65 degree C Audio output (DVD only) : Analogue Audio output(2CH):2.0Vrms
(-22 degree F to 149 degree F)
Installation condition :Horizontal / Relative humidity Audio Input Impedance : More than 47k ohm
under 80% Audio Output Impedance : Less than 1.5k ohm
Weight : 6.45 kg (NET) VHF output : 3 or 4 CH
Playable tape : Very high dense tapes with VHS marks
Dimensions : 430mm Wide X 91mm High Playable disc : DVD,VIDEO-CD,CD(12mm)
X 355.5mm Deep CD(8mm),MP3,CD-R,CD-RW
Tape Speed : SP: 33.35mm/sec.
Recording System SLP : 11.12mm/sec.
4-head Hi Fi : Four video record/playback Maximum Recording Time: T-60: 3 hours/SLP mode
heads T120: 6 hours/SLP mode
Rotary helical scan/luma: FM Fast Forward/Rewind Time : <130sec (T-120 tape)
recording/chroma: converted Tuning System : Auto Program/Cable
subcarrier phase shifted recording Compatible/Frequency
Two audio record/playback Synthesis (FS)
heads Clock display : 12 hrs AM/PM
Rotary helical scan, 2 channels Time Recording : 8 programs a year
FM recording Persistence in power
Received channels :VHF: 2-13 CH / UHF: 14-69 CH failure : 1 min
/ Cable: 1-125 Video S/N (VCR) : Over 45dB(Standard recording)
Video Signal : EIA standard; NTSC color Resolution (VCR) : Over 220 lines (Standard recording)
Antenna : 75 ohm input impedance Resolution (DVD) : Over 500 lines (DVD Disc PLAY)
Video Signal Level : 1Vp-p (140 IRE standard) Audio (VCR) : Over 68dB(Hi-Fi),over 40dB(Mono)
Video output (common use of DVD and VCR): Audio (DVD) : 100dB
VIDEO output terminal, Audio dynamic range : 70dB
1Vp-p (140 IRE standard)
Video output (DVD only):S-VIDEO output
(75 ohm In load Y: 1Vp-p, C:0.286Vp-p)
COMPONENT Progressive output
(75 ohm In load Y:1Vp-p, Pb:0.7Vp-p Pr:0.7Vp-p)
Note : Specifications are subject to change without notice.
CLEANING AND LUBRICATION

2
TEST EQUIPMENT REQUIREMENTS
FIXTURE ITEM DESCRIPTION P/N
Path Adj Fixture Use for X-position adjust/Tape path alignment 97PB396000
Special Driver Use for X-position adjust/Tape path alignment
THE SERVICE FIXTURE
Path Adj Fixture Special Driver
2
AC Millivolt Meter
Sensitivity: 1.0mVAC–400VAC
Dual-Trace Triggered Oscilloscope–with Lo–Cap (X10)
and Direct Probes.
Response: DC–20MHz
Sensitivity: 5mV/div.
Max. Sweep Rate: 0.1µsec./div.
Frequency Counter–7 digits
Sensitivity: 25mV-5V
Range: 50Hz–100MHz
DVM
Range: 0.1VDC–1000VD
Accuracy: 0.5%
NTSC Video Signal Generator–Must provide 1V p-p negative
sync video across a 75 ohm load and produce standard NTSC
75% saturated color bars with a 100% white window.
DC Power Supply
Range: 0-50V, 2A well filtered.
Temperature Controlled Soldering Station–Grounded tip
(Tip temperature: 500°F-600°F).
Note: 500 °F Maximum for leadless components.
AC Variac–Continuously variable.

3
PATH FIXTURE CONNECTION/TEST POINT IDENTIFICATION
1. Preparation for replacement
a. Soldering Iron
Use a pencil-type soldering iron that uses less than 30
watts.
b. Solder
Eutectic solder (Tin 63%, Lead 37%) is recommended.
c. Soldering time
Do not apply heat more than 4 seconds.
d. Preheating
Leadless capacitor must be preheated before installation.
(130°C~150°C, for about two minutes).
2. Removing the leadless component (Resistors, Capacitors)
Grasp the leadless component body with tweezers and alter-
nately apply heat to both electrodes. When the solder on both
electrodes is melted, remove leadless component with a twist-
ing motion.
LEADLESS (CHIP) COMPONENT REMOVAL INSTRUCTION
Note:
a. Leadless component must not be reused after removal.
b. Excessive mechanical stress and rubbing of the compo-
nent electrode must be avoided.
Note:
a. Do not attempt to lift the component off the board until
the component is completely disconnected from the
board by a twisting action.
b. Take care not to break the copper foil on printed board.
• The following procedures are recommended for the replacement of the leadless components used in this unit.
Chip
Tweezers
Soldering lron
Refer to the adjustment of the tape transporting system.
Connect to PT01
!pin-^pin of the
MAIN CIRCUIT BOARD.
CTL pulse test point
GND
S/W pulse test point
ENVE pulse test point
!
^

4
PATH FIXTURE CONNECTION/TEST POINT IDENTIFICATION
3. Installing the Leadless (chip) Component
1) Presolder the contact points of the circuit board.
2) Press the part downward with tweezers and solder both
electrodes as shown below.
4. Removing of Flat ICs(Recommended procedure)
1) For removing solder chips from IC's pins, use a solder
remover or a wiry solder absorber.
2) Heat the IC's tips evenly by moving the chip IC replacing
tool around them, and detach the IC's leads with a tool in
the way of using a lever.
3) Do not reuse ICs removed once (Discard them)
Note:
Do not glue the replacement leadless component to the
circuit board.
Soldering lron
Presolder
Chip IC replacing tool
Soldering lron
Solder
Tweezers

5
LEADLESS (CHIP) COMPONENT IDENTIFICATION
1. Check the followings before S.M.D Troubleshooting
• Cracked or Chipped Component Body
• Cracked or Separated Solder Joints
• Peeling end Terminations or Fractured Leads
2. S. M. D (Surface Mounted Devices) Identification
1) Chip Resistor Identification
* Standard Chip Resistor Code
2) Chip Capacitor Identification
There is no identification of chip capacitor
REMARK Leadless (CHIP) Components are identified on
schematic by means of "(C)" adjacent to symbol
numbers.
• Rejection of Solder from Copper Pads or Component
• Foreign Matter on Copper Pads
• Solder Bridges
= 12x103(1000) = 12000Ω
= 12KΩ
= 47x10° (1) = 47Ω
XXX
123
470
MULTIPLIER (0-9)
2nd SIG. DIGIT (0-9)
1st SIG. DIGIT (1-9)
Examples

6
ABBREVIATIONS
A A or AUD : Audio
A.E. : Audio Erase
AC : Alternating current
ACC : Automatic Color Control
ACS : Auto Clock Set
AFC : Automatic Frequency Control
AFT : Automatic Fine Tuning
AGC : Automatic Gain Control
ALC : Automatic Level Control
AM : Amplitude Modulation
AMP : Amplifier
ANT : Antenna
APC : Automatic phase control
ASS'Y or AS : Assembly
AUTO : Automatic
AV or A/V : Audio/Video
B B : Base, Burst
BAL : Balance
BGP : Burst Gate Pulse
BPF : Bandpass Filter
BW or B/W : Black and White
C C : Capacitor, Chroma, Collector
C Rotary : Color Rotary
C-Sync : Composite Synchronization
CA : Commercial Advance
CAP : Capstan
CAR : Carrier
CATV : Cable Television
CBC : Cable Box Control
CCD : Charge Coupled Devices
CFG : Capstan Frequency Generator
CH : Channel
CHAR : Character
CHROMA : Chrominance
CLK : Clock
CNR : Color Noise Reduction
COMB : Comb Filter
COMP : Comparator, Composite, Compensation
CONV : Converter
CST : Cassette
CTL : Control
CUR : Current
CV : Composite Video
D D : Drum, Digital, Diode, Drain
DC : Direct Current
DD : DC-DC Convert
DEEM or DEEMPH : Deemphasis
DEMOD : Demodulator
DET : Dectector
DEV : Deviation
DFG : Drum Frequency Generator
DOC : Dropout Compensator
DS : Drain and Source
DSSC : Digital Satellite Set Control
dB : Decibel
E EDS : Extended Data System
ENVE : Envelope
E/V : Envelope/Vertical Sync
G GEN : Generator
GND : Ground
H H : High, Horizontal
HA or HEAD AMP : Head Amplifier (PreAmp)
HD : Horizontal Drive, Head
HOR : Horizontal
HZ : Hertz
I I/O : Input/Output
IC : Intergrated Circuit
IF : Intermediate Frequency
INS : Insertion
IR : Infrar Red
K KIL : Killer
L L : Low, Left, Coil
LIM : Limit
LM : Loading Motor
LP : Long Play
LPF : Low Pass Filter
M MA : Movie Advance
MAX : Maximum
MIN : Minimum
MIX : Mixer, Mixing
MMV : Monostable Multivibrator
MOD : Modulation, Modulator
MPX : Multiplex
M/T or MTR : Motor
N NC : None Connection
NC or NOICAN : Noise Canceller
NL : None linear
NR : Noise Reduction
O OSC : Oscillator, Oscillation
OSD : On Screen Display
OSP : On Screen Program
OTR : One Touch Record
P P-P : Peak-to-Peak
PB : Playback
PC : Photo Coupler
PCB : Printed Circuit Board
PG : Phase Generator

7
ABBREVIATIONS
PIC : Picture
PIF : Picture Intermediate Frequency
PLL : Phase Locked Loop
PS : Phase Shift
PWM : Pulse Width Modulator
PWR : Power
Q Q : Transistor
QV : Quasi Vertical
R R : Resistor, Right
REC : Recording
REF : Reference
REG : Regulated, Regulator
REMOCON : Remote Control (Unit)
REV : Reverse
REW : Rewind
RF : Radio Frequency
ROT : Rotary
S SEP : Separation
SHARP : Sharpness
SI or S IN : Serial Input
SO or S OUT : Serial Output
SP : Standard Play
STB : Strobe
SVC : Service
SW or S/W : Switch or Switching Pulse
SYNC : Synchronization
SYSCON : System Control
T TJ : Test Jump
TP : Test Pin
TR : Transistor
TRANS : Transformer
TRK : Tracking
TU : Tuner
U UHF : Ultra High Frequency
V V : Volt, Vertical
V-SYNC : Vertical Synchronization
VCA : Voltage Controlled Adjustor
VCO : Voltage Controlled Oscillator
VCR : Video Cassette Recorder
VD : Vertical Drive
VERT : Vertical
VGC : Voltage Gain Control
VHF : Very High Frequency
VR : Variable Resistor or Volume
W W : Watt
W/D : White and Dark
WF : Wave Form
WHT : White
X X-TAL : Crystal
Y Y FM : Luminance FM Signal
Y Y/C : Luminance/Chrominance

8
INSTRUMENT DISASSEMBLY
Fig. 1 - Legs Removal
Fig. 2 Top Cover Removal
Perform all disassembly procedures in the order presented. When reassembling, use the reverse procedure. Make sure that all
leads/wiring are routed correctly when reassembling.
After Releasing two screws, Disassemble LEG
Release two screws
Release two screws
Release three screws
Releasethreetabs
DisassemblePANELFRONT
Releasethreetabs
Fig. 3 . Panel Front Removal
Release three tabs.
Release three tabs.
Disassemble PANEL FRONT.