Daewoo 14T1, 21Q2, 21Q1, 14T2, 21Q4, 14Q2, 20Q1, 14Q1, 21T2, 20Q3, 20T2 Trouble Shooting Charts, No Raster

Trouble Shooting Charts

1. NO RASTER

CHECK MAIN B+(+123V/+110V) LINE

ABNORMAL
CHECK VOLTAGE AT
(+) OF C807(220∝F 400V)
310Vdc AT AC 220V
	NORMAL
ABNORMAL
	CHECK / REPLACE
CHECK / REPLACE F801	I801(STR-S5707)
FUSE(T4A 250V)	& PERIPHERAL
	COMPONENT
CHECK / REPLACE
D801~D804(1S1888X4)	CHECK /REPLACE
R803(10W 3.3OHM)	I804(PC817)
	D812(BYW 95C)
	R814(2W 56K)

NORMAL

CHECK HEATER VOLTAGE, VIDEO B+(200V) LINE, 16.5V & 48V LINE

ABNORMAL NORMAL

CHECK HORIZONTAL

DRIVE PULSE AT PIN 40

OF I501(TDA8374A)

[REFER TO WAVE

FORM ]

		ABNORMAL		NORMAL
	CHECK HORIZONTAL		CHECK / REPLACE
	Vcc(+8V DC) AT
			R410(1/4W 3.9)
	PIN 37 OF I501
			1401 (2SD1207)
			T401 (TD-10A2)
			Q402 (2SD2499)
ABNORMAL
	CHECK SDA(PIN 8)

CHECK POWER SWITCHING VOLTAGE AT PIN 43 OF I701 *POWER ON; HIGH *STAND-BY ; LOW

NORMAL ABNORMAL

CHECK VOLTAGE(+5V DC)

AT PIN 11 & PIN 37 OF I701

NORMAL ABNORMAL

CHECK SDA(PIN 3)

& SCL(PIN4)

WAVEFORM OF I701

CHECK / REPLACE

X701(20MHz, 18MHz)

CHECK / REPLACE

I802(TDA8138)

I803(KA7808)

ABNORMAL

CHECK / REPLACE D813 (BYV95C) D814 (BYV95C)

R824 (2W 43)

Q802 (KTC 3198Y)

Q803 (KTC 3198Y)

T801 (TSM-4245A)

NORMAL

CHECK / REPLACE I701

& SCL(PIN7)	OK
WAVEFORM OF I501

	CHECK / REPLACE
CHECK / REPLACE
	T402 F.B.T
I501(TDA8374A)
	& CRT

OK

40