Page 1
NOTES) Warning
NOTES) Parts that are shaded are critical
NOTES) With respect to risk of fire or
NOTES) electricial shock.
3-18 3-19
CIRCUIT DIAGRAM
1. POWER(SMPS) CIRCUIT DIAGRAM
IMPORTANT SAFETY NOTICE
WHEN SERVICING THIS CHASSIS, UNDER NO CIRCUMSTANCES SHOULD THE ORIGINAL DESIGN BE
MODIFIED OR ALTETED WITHOUT PERMISSION
FROM THE ZENITH ELECTRONICS CORPORATION
ALL COMPONENTS SHOULD BE REPLACED ONLY
WITH TYPES IDENTICAL TO THOSE IN THE ORIGI-
NALCIRCUITSPECIALCOMPONTS ARE SHADED ON
THE SCHEMATIC FOR EASY IDENTIFICATION.
THIS CIRCUIT DIAGRAM MAY OCCASIONALLY DIFFER FROM THE ACTUAL CIRCUIT USED. THIS WAY,
IMPLEMENTATION OF THE LATEST SAFETY AND
PERFORMANCE IMPROVEMENT CHANGES INTO
THE SET IS NOT DELAYED UNTILTHE NEW SERVICE
LITERATURE IS PRINTED.
NOTE :
1. Shaded( ) parts are critical for safety. Replace only
with specified part number.
2. Voltages are DC-measured with a digital voltmeter
during Play mode.
IC903 PIN3 (AC110V, PLAY)
IC901 PIN3 (AC110V, STAND-BY)
IC902 is defective.
8V Power Line dead.
Q908, R928, D913 and Q909 are defective.
5V Power Line dead.
Q901 and Q902 are defective.
FLD(+), FLD(-) are dead.
Q903, Q904 are defective.
Power control is abnormal.
IC901 is defective.
Power dead.
C927, R918, R922 and
IC905 are defective.
Power dead.
Page 2
3-20 3-21
RF/TE/FE Signal
generation
DRAM
Digital Servo DSP/ CD Decoder
AD Ref.
Voltage Gen
TZC Mirr.
Generator
3.3V Regulator
Spindle Low
Pass Filter
T.E
F.E
R.F
TRACKING LOOP
FOCUS LOOP SPINDLE LOOP
SLED LOOP
Q202 is defective.
DVD LD will not be on.
Q203 is defective
CD LD will not be on
IC403 is defective
No Spindle Full Speed
IC219 is defective
Servo will not operate
IC204 is defective
being slipped during search.
IC209 is defective
AD Converter Error
2. RF & DVD DSP CIRCUIT DIAGRAM
Page 3
3-22 3-23
3. DRIVE CIRCUIT DIAGRAM
SPINDLE
TRACKING
DOOR
FOCUS
SLIED
MOTOR DRIVE
SPINDLE
Page 4
3-24 3-25
4. MPEG & ENCODER CIRCUIT DIAGRAM
3.3V Reg.
No power on
No power on
No power on
No Audio(check clock)
No 5.1CH Audio
No 2CH Audio
Audio signal doesn't appear
No screen
No power on
No power on
No power on
µ-com->MPEG address
The screen is distorted(DVD)
Over 3V->Data error. GND:OK
No VCD screen display(option).
No CD sound out.
Over 3V->Data error. GND:OK
(CD/VCD option)
No power on
µ-com->MPEG command data
No power on
over 3V: normal
No power on
Check 89MHz
No Pb output
No Pr output
No Y output
No composite video output
No Luminance output
in Y/C Video
No Chrominance
output in Y/C Video
Video Mute doesn't
operate in power on/off
VIDEO ENCODER
VIDEO ENCODER
ROM
MPEG2 DECODER
16M SDRAM 16M SDRAM
VIDEO
1
2
3
4
5
7
6
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
CLOCK
No DVD screen display
Page 5
3-28 3-29
5. AUDIO CIRCUIT DIAGRAM
AUDIO 2CH R OUT
AUDIO 2CH L OUT
AUDIO 5.1 CH FR / RR OUT
AUDIO 5.1CH CENTER OUT
AUDIO 5.1CH WOOFER OUT
AUDIO DIGITAL DATA INPUT
CLOCK
DIGITAL DATA OUT
AUDIO 5.1 CH FL / RL OUT
AUDIO DAC
AUDIO DAC
AUDIO DAC
ADC
AUDIO DAC
OPTION
OPTION
IC712, 713 are defective
Audio bad
Q601 is defective
5.1CH FL/FR Audio out bad
IC604 is defective
5.1CH FL/FR Audio out bad
IC705,706,707 are defective
Audio POP noise or 2CH Audio out bad
Q703,704 are defective
Headphone output bad
IC602 is defective
5.1CH RL/RR Audio out bad
IC605 is defective
5.1CH RL/RR Audio out bad
IC708 is defective
Mic input bad
IC710,711 are defective
Digital Data out bad
IC709, 702 are defective
Audio pop noise or Audio
output bad
IC607,608,609,610,611,612 are defective
Audio pop noise or 5.1CH Audio out bad
IC606 is defective
5.1CH woofer/center Audio out bad
IC603 is defective
5.1CH woofer/center Audio out bad
IC703 is defective
2CH Audio out bad
IC601 is defective
5.1CH FL/FR Audio out bad
IC704 is defective
2CH Audio out bad
Q705 is defective
2CH Audio out bad
Page 6
3-30 3-31
6. µ-COM/EXPANDER CIRCUIT DIAGRAM
FLASH ROM
MAIN CPU
SDRAM
E
X
P
A
N
D
E
R
EEPROM
MUX
BCA DECODER
AT49F8192A-90TC/AM29F800BB
GM71C4260CJ60
R197 OPEN
OPTION(DIVX)
Audio output is unstable
Servo will not operate
X101; No Power on
Video output level is unstable
OPEN, Close Error
Servo will not operate
D[00:15] ; FLD Error
A[00:21] ;FLD Error
Page 7
3-32 3-33
7. FRONT(TIMER) & KEY CIRCUIT DIAGRAM
FRONT CONTROL
OPEN/CLOSE
POWER
Remocon
Receiver
RESET
ENTER
4 Direction S/W
SFUTTLE
SW509 is defective
Direction Key is defect
JS500 is defective
SCAN +/- wll not operate
IC501 is defective
Reset Error
RE500 is defective
R/C receiver Error
DIG501 is defective
FLD is distorted
Q500 is defective
LED will not operate
Page 8
3-34 3-35
8. JACK CIRCUIT DIAGRAM
S VIDEO (C)
AUDIO (L)
AUDIO (R)
OPTICAL
COMP.VIDEO
S VIDEO (Y)
EXT/DVD can’t be changed 16:9 can’t be changed Scart Mode can’t be changed
Page 9
IC903 Pin 3
PLAY(AC110V)
3-26 3-27
WAVEFORM
IC901 Pin 3
STAND-BY(AC110V)
(POWER) (VIDEO ENCODER)
(RF/SERVO)
IC201 Pin 21, Focus Error
IC201 Pin 19, SBADD
IC201 Pin 20
Tracking Error
Tek
Stop :
1 00kS/s
3290 Acqs
M 500µs
CH1
280/mV
Record
Length
Fit to Screen
OFF
Time Base
Main
Trigger
Position
50%
Horiz
Scale
(/div)
Horiz
Pos
FastFrame
Setup
more
1 of 3
3
Ch3
1.00V
[ T ]
Record
Length
2500
T
2500
points in
50divs
1000
points in
20divs
500
points in
10divs
IC800 Pin 28 ~ 35 , MPEG Data
IC801 Pin 13 ~ 16 , 19 ~ 22 , MPEG Data
IC800 Pin 10, Composite
IC801 Pin 57, Composite
IC800 Pin 12, Chrominance
IC801 Pin 58, Chrominance
Tek
Stop :
2.50MS/s
4 Acqs
M20.0µs
2 Apr 1999
14:47:27
Glitch
Ch1
Ch3
500mV
[T ]
T
3
IC800 Pin 13, Luminance
IC801 Pin 59, Luminance
IC800 Pin 40, 41 SDA/SCL
IC801 Pin 75, 76 SDA/SCL
Tek
Stop :
1 00kS/s
3290 Acqs
M 500µs
CH1
280/mV
Edge Slope
Type
<Edge>
Source
Ch1
Coupling
DC
Level
280mV
Mode
&
Holdoff
3
Ch3
1.00V
[ T ]
Slope
T
IC800 Pin 43, MPEG Clock(27MHz)
IC801 Pin 71, MPEG Clock(27MHz)
Tek
Stop :
10.0kS/s
13 Acqs
M 5 .00ms
CH1
280/mV
Edge Slope
Type
<Edge>
Source
Ch1
Coupling
DC
Level
280mV
Mode
&
Holdoff
3
Ch3
1.00V
[ T ]
Slope
T
IC800 Pin 49, Vertical SYNC
IC801 Pin 24, Vertical SYNC
Tek
Stop :
2.50MS/s
7 Acqs
M 20.0µs
CH1
280/mV
Edge Slope
Type
<Edge>
Source
Ch1
Coupling
DC
Level
280mV
Mode
&
Holdoff
3
Ch3
1.00V
[ T ]
Slope
T
IC800 Pin 50 Horizontal SYNC
IC801 Pin 59 Horizontal SYNC
IC801 Pin 42 Component Pb
IC801 Pin 43 Component Pr IC801 Pin 44 Component Y
IC201 Pin 20
VBR TRACKING Error
IC201 Pin 28,
RF
IC206 Pin 88, SLED Drive(FMO)
IC202 Pin 18, SLED FG
IC201 Pin 21, Focus Error(in Focus Search)
IC206 Pin 83, Focus Drive(FDO)
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