Daewoo DTH-14Q1FS, Service Manual

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14
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PAL-N system
•If 60[Hz] detected, #21 of the I501 goes up to HIGH level and the system operates as PAL-M or NTSC-M.
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In the case that Base voltage of Q705 is LOW, the voltage driven from R766 and R774 is applied to the #28
of the I701.
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In the case that Base voltage of Q705 is HIGH, according to the voltage change of the #28 of the I701, the
comparator in the I701 switch over the system.
(PAL-M
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NTSC-M, NTSC-M
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PAL-M)
•HIGH signal of the #1 of I701 makes X502 oscillates.(NTSC-M)
•HIGH signal of the #2 of I701 makes X503 oscillates.(PAL-M)
3) FREQUENCY CHARACTERISTICS OF EACH SYSTEM
C. SOUND BLOCK
1. SOUND BLOCK DIAGRAM
2. EXPLANATION OF OPERATION
1) The TV audio signal is detected and goes into the audio switch in I501.
2) The external audio signal from JV01(or JV02) goes into the #12 of I501.
3) The audio switch in I501 alternates audio signals according to the TV/VIDEO control input from the I701.
4) The selected audio signal (#51 of I501) go into the #3 of I601.
SCANNING
LINE
FIELD
CHROMINANCE
COLOR VHF UHF
NUMBER
FREQUENCY
FREQUENCY
SUB CARRIER
(Fh) (Fsc)
NTSC M M 525line 15,734[Hz] 60[Hz] 3.579545[MHz]
PAL M M 525line 15,734[Hz] 60[Hz] 3.575611[MHz]
PAL M 625line 15,625[Hz] 50[Hz] 3.582056[MHz]
I501
LA7688
SIF
EXT.
AUDIO
(JV01/JV02)
FM
DET
AUDIO
SWITCH
I601
TDA7056A
from the µ-COM(#33)
SP
51
12
3
6
8