LG L316 Service manual

LG L316

SECTION1 SUMMARY

KEY TO ABBREVIATIONS

A	AC	:Alternating Current
	ACC	:Automatic Color Control
	ACSS	:Automatic Channel Setting System
	ADJ	:Adjust
	A/E	:Audio Erase
	AFC	:Automatic Frequency Control
	AFT	:Automatic Fine Tuning
	AGC	:Automatic Gain Control
	A.H.SW	:Audio Head Switch
	ALC	:Automatic Level Control
	AM	:Amplitude Modulation
	AMP	:Amplifier
	ANT	:Antenna
	APC	:Automatic Phase Control
	ASS’Y	:Assembly
	AUX	:Auxiliary
B	B	:Base
	BGP	:Burst Gate Pulse
	BPF	:Bandpass Filter
	BS	:Brodcasting Satellite
	BW or B/W	:Black and White
C	C	:Capacitor, Chroma, Collector
	CAN	:Cancel
	CAP	:Capstan
	CAP.BRK	:Capstan Brake
	CAP.RVS	:Capstan Reverse
	CATV	:Cable Television
	CBA	:Circuit Board Assembly
	CCD	:Charge Coupled Device
	C.CTL	:Chro Control, Capstan Control
	CFG	:Capstan Frequency Generator
	CHROMA	:Chrominance
	CNR	:Chroma Noise Redution
	COMB	:Combination
		Comb Filter
	COMP	:Comparator
		Composite
		Compensation
	CONV	:Converter
	C.ROT SW	:Color Rotary Switch
	CS	:Chip Selcet
	C.SYNC	:Composite Synchronization
	CTL DIV	:Control Divide
	CUR	:Current
	CYL	:Cylinder
D	D	:Drum, Digital, Diode, Drain
	D.ADJ	:Drum Adjust
	DC	:Direct Current
	D.CTL	:Drum Control
	DEMOD	:Demodulator
	DET	:Detector
	DEV	:Deviation
	DHP	:Double High Pass
	DIGITRON	:Digital Display Tube
	DL	:Delay line
	DOC	:Drop Out Compensator
	DUB	:Dubbing
	D.V SYNC	:Dummy Vertical Synchronization
E	E	:Emitter
	EE	:Electric to Eletric
	EMPH	:Emphasis
	ENA	:Enable
	ENV	:Envelope
	EP	:Extended Play
	EQ	:Equalizer
	EXP	:Expander
F	F	:Fuse
	FB	:Feed Back
	FBC	:Feed Back Clamp
	FE	:Full Erase
	FG	:Frequency Generator
	FL	:Filter
	FM	:Frequency Modulation
	F/R	:Front/Rear
	FS	:Frequency Synthesizer
	FSC	:Subcarrier Frequency
	F/V	:Frequency Voltage
G	GEN	:Generator
H	H	:High, Horizontal
I	IC	:Integrated Circuit
	IF	:Intermediate Frequency
	INS	:Insert
L	L	:Low, Left, Coil
	LD	:LED
	LD VTG CTL	:Loading Voltage Control
	LECHA	:Letter Character
	L.M	:Level Meter
	LP	:Long Play

	LPF	:Low Pass Filter
M	MAX	:Maximum
	MD	:Modulator
	MECHA.CTL	:Mechanism Control
	MIC	:Microphone
	MIN	:Minimum
	MIX	:Mixer, Mixing
	M.M.	:Monostable, Multivibrator
	MMV	:Mono Multi Vibrator
	MOD	:Modulation, Modulator
	MODEM	:Modulator-Demodulator
	MPX	:Multiplex
N	NR	:Noise Reduction
O	OSC	:Oscillator
	OSD	:On Screen Display
P	PB	:Playback
	PCB	:Printed Circuit Board
	P.CTL	:Power Control
	PRE-AMP	:Preamplifier
	P.F	:Power Failure
	PG	:Pulse Generator
	PLL	:Phase Locked Loop
	PREM.DET	:Premire Detect
	P.P	:Peak-to-Peak
	PS	:Phase Shift
	PWM	:Pulse Width Modulation
	PWR CTL	:Power Control
Q	Q	:Transistor
	QH	:Quasi Horizontal
	QSR	:Quick Setting Record
	QTR	:Quick Timer Record
	QV	:Quasi Vertical
R	R	:Resistor, Right
	RE(or RC)	:Remocon, Receiver
	REC	:Recording
	REC S ‘H’	:Record Start ‘Hight’
	REF	:Reference
	REG	:Regulated, Regulator
	REMOCON	:Remote Control(unit)
	RF	:Radio Frequency
	R/P	:Record/Playback
	RTC	:Reel Time Counter
S	S	:Serial
	S.ACCEL	:Slow Accel
	SAOP	:Second Audio Program
	SC	:Scart, Simulcast
	S.DET	:Secam Detect
	SH	:Shift
	SHARP	:Sharpness
	SIF	:Sound Intermediate Frequency
	SLD	:Side Locking
	S/N	:Signal to Noise Ratio
	SP	:Standard Play
	ST	:Stereo
	SUB	:Subtract, Subcarrier
	SW or S/W	:Switch
	SYNC	:Synchronization
	SYSCON	:System Control
T	T	:Coil
	TP	:Test Point
	TR	:Transistor
	TRK	:Tracking
	TRANS	:Transformer
	TU	:Tuner, Take-up
U	UHF	:Ultra High Frequency
	UNREG	:Unregulated
V	V	:Volt, Vertical
	VA	:Always Voltage
	VCO	:Voltage Controlled Oscillator
	VGC	:Voltage Gain Control
	VHF	:Very High Frequency
	V.H.SW	:Video Head Switch
	VISS	:VHS Index Search
	VPS	:Video Program System
	VR	:Variable Resistor or Volume
	V-SYNC	:Vertical Synchronization
	VTG	:Voltage
	VV	:Voltage to Voltage
	VXO	:Voltage X-tal Oscillator
W	W	:Watt
	WHT	:White
	W/O	:With out
X	X-TAL	:Crystal
Y	Y/C	:Luminance/Chrominance
	YNR	:Luminance Noise Reduction
Z	ZD	:Zener Diode

1-2

IMPORTANT SAFETY PRECAUTIONS

Prior to shipment from the factory, the products are strictly inspected to confrom with the recognized product safety and electrical codes of the countries in which they are to be sold. However, in order to maintain such compliance, it is equally important to implement the following precautions when a set is being serviced.

• Precautions during Servicing

1.Locations requiring special caution are denoted by labels and inscriptions on the cabinet, chassis and certain parts of the product. When performing service, be sure to read and comply with these and other cautionary notices appearing in the operation and service manuals.

2.Parts identified by the symbol and shaded ( Y ) parts are critical for safety. Replace only with specified part numbers.

Note : Parts in this category also include those specified to comply with X-ray emission standards for products using cathode ray tubes and those specified for compliance with various regulations regarding spurious radiation emission.

3.Use Specified internal wiring. Note especially:

1)Double insulated wires

2)High voltage leads

4.Use specified insulating materials for hazardous live parts. Note especially:

1)Insulation Tape

2)PVC tubing

3)Spacers

4)Insulation sheets for transistor

5.Observe that wires do not contact heat producing parts (heatsinks, oxide metal film resistors, fusible resistors, etc.)

6.Check that replaced wires do not contact sharp edged or pointed parts.

7.	1)	When a power cord has been replaced, check
		that A mark is made on the cord, under strain,
		near the aperture, and the flexible cord is
		subjected 100 times to a pull of 40N for a duration	Power code
		of 1 second each.
	2)	During the test, the cord shall not be displaced by
		more than 2mm
8.	Also check areas surrounding repaired locations.		Fig. 1

9.The internal wiring is secured so as not to approach the heating parts and high voltage parts by its shape. So, these wires must be restored to its former state.

1-3

SAFETY CHECK AFTER SERVICING

Examine the area surrounding the repaired location for damage or deterioration. Observe that screws, parts and wires have been returned to original positions. Afterwards, perform the following tests and confirm the specified values in order to verify compliance with safety standards.

• Insulation resistance test

confirm the specified insulation resistance or greater between power cord plug prongs and externally exposed parts of the set (RF terminals, antenna terminals, video and audio input and output terminals, incrophone jacks, earphone jacks, etc.) See table below.

• Dielectric strength test

Confirm specified dielectric strength or greater between power cord prongs and exposed accessible parts of the set (RF terminals, antenna terminals, video and

audio input and output terminals, incrophone jacks,

earphone jacks, etc.) See table below.

d

• Clearance distance

Primary

circuit terminals

When replacing primary circuit components, confirm

Chassis

specified clearance distance (d), (d') between sol-

a

dered terminals, and between terminals and sur-

rounding metallic parts. See table below.

Table 1 : Ratings for selected areas

Fig. 2

AC Line Voltage

Region

Insulation

Dielectric

Clearance

Resistance

Strength

Distance(d),(d)

*100 to 130 V

Europe

F

10 MΩ/500 V DC

4kV 1 minute

F 6mm(d)

*200 to 240 V

Australia

F 8mm(d)

(a Power cord)

*Class II model only.

Note. This table is unofficial and for reference only. Be sure to confirm the precise values for your particular country and locality.

•Leakage Current test

Confirm specified or lower leakage current between B(earth ground, power cord plug prongs) and externally exposed accessible parts (RF terminals, antenna terminals, video and audio input and output terminals, microphone jacks, earphone jacks, etc.)

Exposed

Measuring Method: (Power ON)

accessible

part

Z

AC Voltmeter

Insert load Z between B(earth ground, power cord

Load

plug prongs) and exposed accessible parts. Use an

Earth

Ground,

AC voltmeter to measure across both terminals of

Power cord plug prongs

load Z. See figure and following table.

B

Table 2:Leakage current ratings for selected areas.

Fig. 3

AC Line Voltage

Region

Load Z

Leakage Current(i)

Earth Ground

(B) to :

100 to 130 V

Europe

i E 0.7m A peak

Antenna earth

2kΩ

i E 2m A DC

terminals

200 to 240 V

Australia

i E 0.7m A peak

Other terminals

50k

i E 2m A DC

Ω

Note. This table is for IEC member only. Be sure to confirm the precise values for your particular country and Note. locality.

1-4

SERVICE NOTICE ON REPLACING EEPROM

In case that defective EEPROM of PAL models is replaced, to operate these sets from the initial state MP KEY must be repaired as well before delivering to the customer.

If MP KEY isn’t repaired the setting of RF OUT channel or LANGUAGE might be different from that for custormer’s country.

•MP KEY : In case of PAL VCR if holding the REC button on the front panel and the CLEAR button on the remote control handset for 5 ~ 7 seconds with power being switch all and no tapes,

OK is displayed at FLD for FLD models and LED becomes on for LED CLOCK models. This is the state that initializing EEPROM is finished.

(In case of PAL VCP if holding the REC button on the front panel and the MENU button on the remote control handset for 5 ~ 7 seconds with power being off and no tapes, All the LED DOTs become on. This is the state that initializing EEPROM is finished.)

•MP KEY's function : MP KEY sets EEPROM's data up to the initial state.

OK

•FLD MODEL:

MP KEY “OK”

		TIMER			• LED CLOCK MODEL:
REC
					MP KEY Switch all on a Light
VCR			AM

• LED DOT MODEL:

MP KEY Switch all on a Light

1-5

PREDICTED ERRORS OF MODULATOR & HOW TO COPE WITH THEM

CONTENT

Handle RF OUT CH by each region

For G : 30 ~ 40 ch For I : 30 ~ 40 ch 30 ~ 40 ch

For G/K : 30 ~ 40 ch (G-initial for Australia) 30 ~ 40 ch (K-initial for CIS)

30 ~ 40 ch (G-initial for Southeast asia)

PREDICTED ERRORS

1.In RF Inteference, it is impossible to control from the outside.

2.After forwarding models with G/K system for G/K, it is difficult to change system.

HOW TO HANDLE

1.To subdivide CH according to model and region.

2.To adjust CH or System after open the top case.

1-6

	SPECIFICATIONS
General
Power ....................................	AC110~240V, 50/60Hz
Power consumption ..............	Approx. 10 Watts
Dimensions (W x H x D) .......	360 x 94 x 230 mm
Weight ...................................	Approx. 3.0 Kg.
Operating temperature..........	5 ~ 35°C
Operating humidity................	Less than 80%
Video
Television system..................	CCIR standard (625 lines, 50 fields), PAL/SECAM colour signal
Recording format ..................	PAL/MESECAM/NTSC3.58/NTSC4.43
RF OUT.................................	PAL/SECAM(G or K)
Input level..............................	1.0Vp-p, 75 Ohm, unbalanced
Output level ..........................	1.0Vp-p, 75 Ohm, unbalanced
RF modulator ........................	UHF channels 32~40 (adjustable)
Audio
Input level..............................	-6 dBm, more than 47 kOhms
Output level...........................	-6 dBm, less than 1.5 kOhms
Audio track ...........................	Mono track
Audio frequency response ....	100 Hz ~ 10kHz(-6/+3 dBm)

• Design and specifications are subject to change without notice.

1-8

SECTION2 CABINET & MAIN FRAME

SERVICE METHOD

(1) Disassembly Flow

Top Case

Bottom Cover

Front Panel

Housing & Deck

Assembly

Main C.B.A

LED C.B.A

(2) Re-assembly Flow for service like Fig. 2-1

LED C.B.A

Main C.B.A

Housing & Deck

Assembly

(3)To check and replace Electrical parts

1Disassemble the unit according to No.1) Disassembly Flow.

2Re-assemble the unit according to No.2) Re-assembly Flow.

3Place the unit like Fig. 2-1

4Check and replace Electrical parts.

NOTE :

1Insert Video Cassette Tape inversely like Fig. 2-1 to check and replace defective parts.

2In disassembling and reassembling, be careful not to damaged CST switch.

(Positioned Upside Down)

C.B.A Princioal

Housing y Mecanismo

Cassette Tape

(Upside Down)

Fig.2-1

2-1

5

4

3

2

1

EXPLODED VIEWS

1. Cabinet and Main Frame Section

462

250

A46

320

462 457

NOTE) Refer to “SECTION 5 REPLACEMENT PARTS LIST” in order to look for the part number of each part.

_ OPTIONAL PARTS

300

		330
464
261	260	452
457
A00		A49
		A42

A43

284

283

280

A

B

C

D

2-2

2. Packing Accessory Section

810 CABLE SET ASS'Y

801 INSTRUCTION ASS'Y

808 BATTERY

(Optional Parts)

803 PACKING ASS'Y

900 REMOCON

804 SHEET CUSHION

802BOX CARTON

•Packing Accessory Section Part List

2-4

SECTION 3 ELECTRICAL

ELECTRICAL ADJUSTMENT POINTS ARRANGEMENT

:Measurement point

:Adjustment point

		A/V JACK	M
			O
SMPS	AVCP		D
		Hi-Fi	U
	DECK CNT.		L
			A
S	A/V	MODULATOR	T
			O
M			R
P
S	SYSTEM
		U-COM
	DISP
KEY		KEY
BOARD(L)		BOARD(R)

3-1

ELECTRICAL ADJUSTMENT PROCEDURES

1.Servo Adjustment

1)PG Adjustment

• Test Equipment

a) OSCILLOSCOPE

b) PAL TEST TAPE (VHS SP)

• Adjustment And Specification

	MODE	MEASUREMENT POINT	ADJUSTMENT POINT	SPECIFICATION
	SP TAPE PLAY	V.Out Jack	AUTO	PAL PG : 416 ± 32usec
		H/SW(W373, W374)		NTSC : 412 ± 32usec

•Adjustment Procedure and Caution a) Insert the PAL SP Test Tape and play.

Note - Adjust the distance of X, pressing SET REC KEY and “OK” on RCU simultaneously. (3SEC HOLD). In ININTIAL MODE, LED of POWER/CST IN/LP/EP/STANDBY is on .(TRK PRESET MODE)

b) In TRK PRESET MODE,Pressing SET REC KEY and “OK” on RCU same, and then PG is adjusted automatically. (LED of PLAY/REC is off.)

c) Connect the CH1 of the oscilloscope to the H/SW(W373, W374) and CH2 to the Video Out for the VCR. d) Trigger the mixed Video Signal of CH2 to the CH1 H/SW(W373, W374), and then check the distance (time difference), which is from the selected A(B) Head point of the H/SW(W373, W374) signal to the

starting point of the vertical synchronized signal, to 416 µsec ± 32 µsec.

•WAVEFORM

t=416 sec ± 32 sec

• CONNECTION

VIDEO
OUT
W373/W374	CH-1 CH-2

Fig. 3-2

3-2