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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 CIRÂCUMSTANCES 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 DIFÂFER 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.
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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