Lg Ck57 User manual

SERVICE MANUAL

MINI HI-FI SYSTEM

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS”

IN THIS MANUAL.

Only for training and service purposes.

CONFIDENTIAL

P/NO : AFN78432907 MARCH, 2017

MODEL: CK57 (CK57, CKS57F/W)

MODEL: CK57

(CK57, CKS57F/W)

“Any reproduction, duplication, distribution (including by way of email, facsimile or other

electronic means), publication, modification, copying or transmission of this Service Manual is

STRICTLY PROHIBITED unless you have obtained the prior written consent of the LG Electronics

entity from which you received this Service Manual. The material covered by this prohibition includes,

without limitation, any text, graphics or logos in this Service Manual.”

CONTENTS

SECTION 1 ........ GENERAL

SECTION 2 ........ CABINET & MAIN CHASSIS

SECTION 3 ........ ELECTRICAL

1-1

Only for training and service purposes.

SECTION 1

SUMMARY

CONTENTS

SERVICING PRECAUTIONS ............................................................................................................................ 1-3

ESD PRECAUTIONS......................................................................................................................................... 1-5

HIDDEN KEY MODE ......................................................................................................................................... 1-6

1. HIDDEN KEY MODE TABLE

2. HIDDEN KEY MODE DESCRIPTION

PROGRAM DOWNLOAD GUIDE...................................................................................................................... 1-7

FOTA UPDATE STEP USING BT APP ............................................................................................................ 1-9

SPECIFICATIONS ........................................................................................................................................... 1-11

1-2

Only for training and service purposes.

1-3

Only for training and service purposes.

NOTES REGARDING HANDLING OF THE PICK-UP

1. Notes for transport and storage

1) The pick-up should always be left in its conductive bag until immediately prior to use.

2) The pick-up should never be subjected to external pressure or impact.

2. Repair notes

1) The pick-up incorporates a strong magnet, and so should never be brought close to magnetic materials.

2) The pick-up should always be handled correctly and carefully, taking care to avoid external pressure and

impact. If it is subjected to strong pressure or impact, the result may be an operational malfunction and/or

damage to the printed-circuit board.

3) Each and every pick-up is already individually adjusted to a high degree of precision, and for that reason

the adjustment point and installation screws should absolutely never be touched.

4) Laser beams may damage the eyes!

Absolutely never permit laser beams to enter the eyes!

Also NEVER switch ON the power to the laser output part (lens, etc.) of the pick-up if it is damaged.

5) Cleaning the lens surface

If there is dust on the lens surface, the dust should be cleaned away by using an air bush (such as used

for camera lens). The lens is held by a delicate spring. When cleaning the lens surface, therefore, a cot-

ton swab should be used, taking care not to distort lens.

6) Never attempt to disassemble the pick-up.

Spring has excess pressure. If the lens is extremely dirty, apply isopropyl alcohol to the cotton swab.

(Do not use any other liquid cleaners, because they will damage the lens.) Take care not to use too much

of this alcohol on the swab, and do not allow the alcohol to get inside the pick-up.

Storage in conductive bag Drop impact

NEVER look directly at the laser beam, and don’t allow

contact with fingers or other exposed skin.

Magnet

How to hold the pick-up

Conductive Sheet

Cotton swab

Pressure

SERVICING PRECAUTIONS

NOTES REGARDING COMPACT DISC PLAYER REPAIRS

1. Preparations

1) Compact disc players incorporate a great many ICs as well as the pick-up (laser diode). These components

are sensitive to, and easily affected by, static electricity. If such static electricity is high voltage, components

can be damaged, and for that reason components should be handled with care.

2) The pick-up is composed of many optical components and other high-precision components. Care must be

taken, therefore, to avoid repair or storage where the temperature or humidity is high, where strong magne-

tism is present, or where there is excessive dust.

2. Notes for repair

1) Before replacing a component part, first disconnect the power supply lead wire from the unit

2) All equipment, measuring instruments and tools must be grounded.

3) The workbench should be covered with a conductive sheet and grounded.

When removing the laser pick-up from its conductive bag, do not place the pick-up on the bag. (This is

because there is the possibility of damage by static electricity.)

4) To prevent AC leakage, the metal part of the soldering iron should be grounded.

5) Workers should be grounded by an armband (1 M)

6) Care should be taken not to permit the laser pick-up to come in contact with clothing, in order to prevent

static electricity changes in the clothing to escape from the armband.

7) The laser beam from the pick-up should NEVER be directly facing the eyes or bare skin.

Resistor

(1 M)Conductive

Sheet

Resistor

(1 M)

Armband

1-4

Only for training and service purposes.

1-5

Only for training and service purposes.

Electrostatically Sensitive Devices (ESD)

Some semiconductor (solid state) devices can be damaged easily by static electricity. Such components

commonly are called Electrostatically Sensitive Devices (ESD). Examples of typical ESD devices are integrated

circuits and some field-effect transistors and semiconductor chip components. The following techniques should

be used to help reduce the incidence of component damage caused by static electricity.

1. Immediately before handling any semiconductor component or semiconductor-equipped assembly, drain off

any electrostatic charge on your body by touching a known earth ground. Alternatively, obtain and wear a

commercially available discharging wrist strap device, which should be removed for potential shock reasons

prior to applying power to the unit under test.

2. After removing an electrical assembly equipped with ESD devices, place the assembly on a conductive surface

such as aluminum foil, to prevent electrostatic charge buildup or exposure of the assembly.

3. Use only a grounded-tip soldering iron to solder or unsolder ESD devices.

4. Use only an anti-static solder removal device. Some solder removal devices not classified as "anti-static" can

generate electrical charges sufficient to damage ESD devices.

5. Do not use freon-propelled chemicals. These can generate electrical charges sufficient to damage ESD

devices.

6. Do not remove a replacement ESD device from its protective package until immediately before you are

ready to install it. (Most replacement ESD devices are packaged with leads electrically shorted together by

conductive foam, aluminum foil or comparable conductive materials).

7. Immediately before removing the protective material from the leads of a replacement ESD device, touch the

protective material to the chassis or circuit assembly into which the device will by installed.

CAUTION : BE SURE NO POWER IS APPLIED TO THE CHASSIS OR CIRCUIT, AND OBSERVE ALL OTHER

SAFETY PRECAUTIONS.

8. Minimize bodily motions when handing unpackaged replacement ESD devices. (Otherwise harmless motion

such as the brushing together of your clothes fabric or the lifting of your foot from a carpeted floor can generate

static electricity sufficient to damage an ESD device).

CAUTION. GRAPHIC SYMBOLS

THE LIGHTNING FLASH WITH APROWHEAD SYMBOL. WITHIN AN EQUILATERAL TRIANGLE, IS

INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF UNINSULATED

“DANGEROUS VOLTAGE” THAT MAY BE OF SUFFICIENT MAGNITUDE TO CONSTITUTE A RISK OF

ELECTRIC SHOCK.

THE EXCLAMATION POINT WITHIN AN EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE

SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE

LITERATURE.

ESD PRECAUTIONS

1-6

Only for training and service purposes.

2. HIDDEN KEY MODE DESCRIPTION

2-1. Version Check

- Function : Version Check.

- Entrance Key : Front ‘Stop’ + Remote Control Key ‘Play’ for 5s.

- Exit Key : Remote Control Key ‘Play’ for 1.5s.

- Operation explanation : Remote Control Key OR .

2-2. EEPROM Initial

- Function : Initialize data stored in EEPROM and BACKUP RAM data.

- Entrance Key : Front ‘Stop’ + Remote Control Key ‘ ‘ for 5s.

- Exit Key : Auto exit.

- Explanation : ‘E2P CLR’ is displayed on the VPD and turn off the power automatically.

HIDDEN MODE ENTRANCE KEY(Audio) EXIT KEY

Version Check Front ‘Stop’ 

+ Remote Control Key ‘Play’ for 5s Remote Control Key ‘Play’ for 1.5s

EEPROM INITIAL Front ‘Stop’ 

+ Remote Control Key ‘ ‘ for 5s Auto exit

1. HIDDEN KEY MODE TABLE

HIDDEN KEY MODE

1. USB PROGRAM

Download program file name must be HG840_CK57_YYMMDDX.bin

If security program(Water Wall) is activated on PC, you must save the file to the USB storage device

and disable the security software, then download the file to your set.

Downloading file proceeds in the same way at USB1 function and USB2 function.

Caution:

When downloading the file, you should neither unplug the USB device, change to the other function,

nor power off the device. USB device must be unplugged when the downloading process is completed.

ON VFD DISPLAY SCREEN

1) (Fast) Format USB device.

2) Copy Firmware file to USB device.

NO USB

Insert USB device at USB function.



MCS



FINISH



AUTO POWER OFF

1-7

Only for training and service purposes.

PROGRAM DOWNLOAD GUIDE

2. EQ & DEMO PROGRAM

Download program file name must be EQ_PRG.BIN

If security program(Water Wall) is activated on PC, you must save the file to the USB storage device

and disable the security software, then download the file to your set.

Downloading file proceeds in the same way at USB1 function and USB2 function.

Caution:

When downloading the file, you should neither unplug the USB device, change to the other function,

nor power off the device. USB device must be unplugged when the downloading process is completed.

ON VFD DISPLAY SCREEN

1) (Fast) Format USB device.

2) Copy Firmware file to USB device.

NO USB

Insert USB device at USB function.



EQDEMOUP



FINISH



AUTO POWER OFF

1-8

Only for training and service purposes.

1-9

Only for training and service purposes.

FOTA UPDATE STEP USING BT APP

Step1 : App connecting

(Check FW version)

After connecting the BT App with SET,

the user could ﬁnd the “Device Version info” on

Setting tab.

Step3 : Select update button

When touch the “Update” button, user could

update the SET ﬁrmware using FOTA.

Step2 : Device version info

When touch the “Device Version info” button,

user could ﬁnd the current and latest SET

version on pop-up menu.

Step4 : Conﬁrm update

Select the OK button on the caution message.

1-10

Only for training and service purposes.

Step5 : Download from CDN server

1st step is download from CDN server to

smart phone. The progress bar is displayed

on BT App.

Step7 : FW Flash Writing Step8 : FOTA complete

After completed the download from the smart

phone, the SET overwrite the ﬁrmware to ﬂash

memory.

When ﬁnishing the ﬂash memory writing, pop-up

message about ﬁnish is displayed and the SET

auto power off.

Step6 : Transfer FW

After completed the download from server,

smart phone start to transfer the ﬁrmware to the

SET. The progress bar is displayed on BT App.

SPECIFICATIONS

1-11

Only for training and service purposes.

•GENERAL

Power requirements 120 V ~ 60 Hz

Power consumption 105 W

Dimensions (W x H x D) Approx. 350 mm x 166 mm x 276 mm

Operating temperature 5 °C to 35 °C

Operating humidity 60 %

•INPUTS

Analog audio in (AUX IN) 2.0 Vrms (1 kHz, 0 dB), 75 Ω, RCA jack (L, R)

Portable in (PORTABLE IN) 1.0 Vrms (3.5 mm stereo jack) x 1

Microphone (MIC) Sensitivity 20 mV (1 kHz), 6.3 mm jack x 1

•TUNER

FM Tuning Range 87.5 to 108.0 MHz or 87.50 to 108.00 MHz

AM Tuning Range 522 to 1,620 kHz, 520 to 1,710 kHz or 522 to 1,710 kHz

•SYSTEM

Frequency Response 40 to 20,000 Hz

Signal-to-noise ratio More than 75 dB

Dynamic range More than 75 dB

Bus Power Supply (USB) 5 V 500 mA

•AMPLIFIER (RMS Output power)

Total output 1,100 W RMS

Front 350 W RMS X 2 (4 Ωat 1 kHz, 25 % THD)

Subwoofer 400 W RMS (3 Ωat 60 Hz, 25 % THD)

•FRONT SPEAKER

Type 2 Way 2 Speaker

Impedance 4 Ω

Rated Input Power 350 W RMS

Max. Input power 700 W RMS

Dimensions (W x H x D) Approx. 300 mm x 363 mm x 256 mm

•SUBWOOFER SPEAKER

Type 1 Way 1 Speaker

Impedance 3 Ω

Rated Input Power 400 W RMS

Max. Input power 800 W RMS

Dimensions (W x H x D) Approx. 310 mm x 363 mm x 256 mm

•Design and specifications are subject to change without notice.

1-12

Only for training and service purposes.

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

EXPLODED VIEWS ........................................................................................................................................... 2-3

1. CABINET AND MAIN FRAME SECTION ................................................................................................. 2-3

2. PACKING ACCESSORY SECTION ......................................................................................................... 2-7

3. SPEAKER SECTION ................................................................................................................................ 2-8

DISASSEMBLY INSTRUCTIONS ................................................................................................................... 2-10

ASSEMBLY INSTRUCTIONS ......................................................................................................................... 2-19

2-1