Service manual

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NOTES) Symbol denotes AC ground.
NOTES) Symbol denotes DC chassis ground.
NOTE) Warning
NOTE) Parts that are shaded are critical
NOTE) With respect to risk of fire or
NOTE) electricial shock.
OPTIONAL TABLE
CIRCUIT DIAGRAMS
1. POWER(SMPS) CIRCUIT DIAGRAM 1
Switching Error.
IC101 is defective.
Switching Error.
IC104 is defective.
Switching Error.
IC105, 106 are defective.
No Power.
F101 is defective.
No 5.3VA.
D127 is defective.
No 3.8VA.
D127 is defective.
No 13VA.
D126 is defective.
No 33VA.
D125 is defective.
No 32VA.
D122 is defective.
Digitron Error.
D123, F102, ZD121, D124 are defective.
No power.
BD101, TH101 are defective.
IMPORTANT SAFETY NOTICE
WHEN SERVICING THIS CHASSIS, UNDER NO CIR-
CUMSTANCES SHOULD THE ORIGINAL DESIGN BE
MODIFIED OR ALTERED WITHOUT PERMISSION
FROM THE ZENITH ELECTRONICS CORPORATION.
ALL COMPONENTS SHOULD BE REPLACED ONLY
WITH TYPES IDENTICAL TO THOSE IN THE ORIGI-
NAL CIRCUIT. SPECIAL COMPONENTS ARE SHADED
ON THE SCHEMATIC FOR EASY IDENTIFICATION.
THIS CIRCUIT DIAGRAM MAY OCCASIONALLY DIF-
FER FROM THE ACTUAL CIRCUIT USED. THIS WAY,
IMPLEMENTATION OF THE LATEST SAFETY AND
PERFORMANCE IMPROVEMENT CHANGES INTO
THE SET IS NOT DELAYED UNTIL THE 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.