Eiki LC-NB3E service manual No Sound, Lens Motor Problems

Troubleshooting

No Sound

1. No audio signals at AV input circuit.

Check audio signals at pins14 and 15 of IC5011 on AV Board. Check IC5011 and peripheral circuits.

2.Incorrect operation of VIDEO/COMPUTER mode switching.

Check AV/PC switching signal at pins 10 and 11 of IC5011. Check IC5011, IC801 and switching signal.

AV : Low, PC : High

3.No audio output signal at speaker.

Check audio signal at pins 1 and 3 of K8F on Main Board. Check MUTE signal at pin 4 of IC031.

Mute On : High

Check MUTE signal at pin 7 of IC1831, pins 7 and 13 of IC1881, and peripheral circuit.

Mute On : High

Check sound volume signal at pins 27, 28 of K10U, and pin 14 of IC1831.Check IC IC001, IC031 and peripheral circuit.

Volume Min.: Low

4.No power supply at audio circuit.

Check 6V(6V AUDIO) power supply line.

AV BOARD		IC5011							AV SUB BOARD				IC2161			MAIN BOARD
								IC001		IC031			D/A
		AUDIO-SW		Q5072	Q5071											Q1817
								AUDIO
			10							AUDIO						Q1817
COMPUTER	PC_L/R				AV/PC			PRE-AMP.		CONTROL					SCL2_5
		1	11				K10X						77	13		79,78
															SDA2_5
AUDIO IN		13									L		8
			15		Q5031	3	Q011		5	17	18
								1, 7					AV/PC
			14		Q5042	4	Q021				R
									3
VIDEO	AV_L/R	2								14	13
AUDIO IN		12			K10Y			2	2, 6		4
			9										PC: H			IC801
		Q2051									MUTE
						7							AV: L
						6										SUB
EXTERNAL						8
						10							IC1831			CPU
SPEAKER						11
								K10U		K3U			D/A
					AV/PC				29							Q1818
									30
							VOLUME						14			Q1819
									27						SCL1_5
									28					2		80,81
														3	SDA1_5
							MUTE On: H			MUTE			AUDIO MUTE
									31
									32		7	13	7
									21				MUTE On: H
											K8F IC1881
									24
										1,3	BUFFER
SPEAKER

Lens Motor Problems

1.No drive signals supplied at motors

Check drive signals at pins 1 to 4 of K6U on Power Board. Check ICs IC5501, IC5551 and peripheral circuits. Check motor drive power supply (9VMCI).

2.No drive signals supplied at motor drive ICs.

Check drive signals at pins 3-4 (ZOOM), 5-6 (FOCUS) of k6S. Check IC801.

3.No drive signals output from CPU.

Check drive signals at pins 29,30, 33, 34 of IC801(SUB CPU). Check IC801.

4.No key switch signals input to CPU.

Check signals at pins 50 to 52 of IC801 when pressing the key buttons. Check key buttons.

Logic Table of IC5501/IC5551

	Input		Output		Operation
4		5	7	1
H		L	L	H	Forward drive
L		H	H	L	Reverse drive
H		H	L	L	Braking
L		L	-	-	Stand by

FOCUS MOTOR

M

ZOOM

MOTOR

M

1

2

3

4

			Power	LEVEL +
	15V		Supply	LEVEL -
			Circuit	KEY SW BOARD
Q65A
	Q65B	Q65C

					IC1881
		ON: H		BUFFER
9V MCI	IC5551					POWER
		5V_SW	15	3	17		1
	FOCUS		16			ON: H
	MOTOR DRIVE

K6U		3		K6S K8S		FOCUS +
		1	4		6		33	52
						FOCUS -
		7	5		5		34	51
							IC801	50
		IC5501					SUB CPU
		ZOOM
	MOTOR DRIVE
		3	4			ZOOM +
		1			4		29
						ZOOM -
		7	5		3		30

POWER BOARD

FOCUS

ZOOM

K68A

3	4	5
3	4	5

K8A

MAIN BOARD

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