Daewoo DTH-14Q1FS, Service Manual

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10
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DESCRIPTION OF CIRCUIT OPERATION
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FEATURE OF THE CM-537
•VIDEO, CHROMA, DEFLECTION in one-chip IC.
•Automatic switching of 3-SYSTEM(NTSC, PAL-M, PAL-N).
•FS(Frequency Synthesizer ) Tunning System.
•Function of LAST MEMORY against the electric failure (E
2 PROM:24LC028).
•Separation of PIF and SIF(SAW filter :DSW1013P)
•Minimization of Ringing by applying Ringing-less FBT(2001SPND)
•Auto-compensation of the vertical height level against the frequency change of AC power .
•OVER CURRENT PROTECTION Circuit.
•Elimination Circuit of POP NOISE.
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OPERATION CHARACTERISTICS OF EACH BLOCK
A.
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-COM BLOCK
1.
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-COM(DMC42C522N, I701) PIN DESCRIPTION/OPERATION
PIN NAME/(ABBREV) FUNCTION REMARK
1 NTSC-M 3-SYSTEM SWITCHING CMOS
(RCO/PWM14) PUSH PULL
2 PAL-M 3-SYSTEM SWITCHING CMOS
(R83) PUSH PULL
3 AC POWER DOWN MAIN POWER DOWN Detect input:active LOW CMOS
(R03/INT3) PUSH PULL
4 SD INPUT SYNC. signal INPUT H: signal detect
(RO2/INT2) L: no signal
5 REMOTE CONTROL REMOTE CONTROL signal input
INPUT REMOTE CONTROL IC : M50560-388GP/M50560-001
(R01/INT1TIM1) (CUSTOM CODE: 14H)
6 KEY RETURN IN 0 ·KEY MATRIX COLUMN 0
(R00/INT0/TIM0) ·HOLD MODE : WAKE-UP using INT1 PUSH PULL
7 Xin SYSTEM CLOCK : 4.1943 MHz
8 Xout
9 RESET SYSTEM RESET
10 KEY RETURN IN 1 KEY MATRIX COLUMN 1
(R82)
11 Vss GND
12 KEY RETURN IN 2 KEY MATRIX COLUMN 2
(R81)
13 KEY SCAN OUT 0 · KEY MATRIX ROW 0
& TIMER · Active HIGH when ON TIMER is set.
(R80)