LG LH70A Service Manual

SERVICE MANUAL

CAUTION

BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL.

Internal Use Only

Website http://biz.lgservice.com

AUGUST, 2015

MODEL: LH70A (LH70A, LH70A-S)

MODEL: LH70A

(LH70A, LH70A-S)

Multimedia Speaker System

P/NO : AFN77277035

CONTENTS

SECTION 1 ........ GENERAL

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

SECTION 3 ........ ELECTRICAL

SECTION 4 ........ REPLACEMENT PARTS LIST

1-1

SECTION 1

GENERAL

CONTENTS

ESD PRECAUTIONS ......................................................................................................................................... 1-3

HIDDEN KEY MODE ......................................................................................................................................... 1-4

THE PROCESS OF UPDATING SOFTWARE .................................................................................................. 1-5

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

1-2

ESD PRECAUTIONS

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.

1-3

HIDDEN KEY MODE

1. Software Version

After Power On, Press Woofer front Play/Pause button + RCU Play/Pause button during 5seconds. Then, you can see the SW version on LED display. (Ex. “00 09”)

2. Factory Reset

After Power On, Press Woofer front Play/Pause button + RCU FUNC button during 5seconds. Then,  Factory reset will be executed and  you can see the Checksum of SW version on LED display. (Ex. “46 48”) Finally,  it will be turned off automatically.

3. FM Stereo On/Off

At FM mode, Press Woofer front Play/Pause button or RCU Play/Pause button shortly. Then, you can see the changed state of stereo on LED display. (Ex. “St On”)

1-4

THE PROCESS OF UPDATING SOFTWARE

1. Upgrade MCU software

1-1. Install Update Program on PC.

1) Execute Jetronic8FXProgrammerVer1.0.exe ﬁ le.

2) Install USB to COM Driver.

- Execute Setup.exe ﬁ le.

1-3.

Power on the Jetronic8FX, and Connect to PC.

Make sure the driver is installed and COM is available. Generally, COM port number is less than 10. Select an available COM which is not in use.

1-4. Execute Jetronic8FX programmer.

1-2. Download device interface description.

1-5. Download updating software to programming device.

1. MCU Type: MB95F013K

2. “File”  “Open File”, choose download x.mhx ﬁ le (Example: MB95F013K.mhx)

3. Baud rate: 62500bps

4. Voltage: default 5 V

5. Step: default

6. Device to connect the PC OK!

7. “Download”: down ﬁ le to device.

8. Success!

1-5

1-6. Download updating software to LH70A.

1) Connect programming device to LH70A.

2) Power ON programming device.

3) LH70A without access to electricity.

5) The LCD shows program success and blue light is normally on.

1-7. If blue light turns red and buzzer "di" three times and the LCD shows handshake fail, burning is failed. Then repeat step 1-6.

4) Press the download button. The LCD shows programming and blue light ﬂ icker.

1-8. If updating is successful and another speaker needs update, then repeat step 1-6.

1-6

2. Upgrade USB software

2-1. Install Update Program on PC.

Execute Setup.exe ﬁ le in ProductTool_V5.42 folder.

2) Identify connected USB port at ﬁ rst time.

3) Select SW update ﬁ le with "..." button.

2-2. Plug out Power Cord and connect LH70A to PC via USB cable.

2-3. Using Update Program, do SW update.

1) execute Mass Product Tool.

4) Replace SW update ﬁ le in Update Program.

1-7

5) Check USB device connected

and click DOWNLOAD button.

1-8

3. Upgrade Bluetooth software (Optional Part)

3-1. Install Update Program on PC.

1) Execute InstallBlueSuite_2_5_8_667.exe ﬁ le

3-2. Insert PCB correctly.

3-5. Enter DFU mode.

BT mode & Press TUNING- until “dFU” display on LED.

3-6. PC will install the driver automatically.

3-3. Connect LH70A to PC via USB cable.

3-4. Enter factory test mode.

USB mode & no USB & Press TUNING- and TUNING+ during 5 seconds.

3-7. Using Update Program, do SW update.

1) Execute PSTool.

1-9

3-8. Choose USB. There is \\.\csr0 in port if successful. Then we can read Bluetooth address and record it. We must restore it after device upgraded.

3-10. Restore Bluetooth Address.

3-9. Choose File  Merge in turn. Select SW update ﬁ le with "Open" button. We can read Bluetooth Address which matches the latest MCU version number.

3-11. Restore Bluetooth Name.

- Enter “name” in Filter and modify Bluetooth name.

3-12. Power off to exit the DFU mode.

1-10

SPECIFICATIONS

Auto power down

This unit will turn itself off to save electricity in the case were the main unit is not connected to an external device and is not used for 20 minutes. The unit will also turn itself off after six hours if the Main unit has been connected to another device using the analog inputs.

Product type 2,1 speaker system

Power Supply 110 -240 V ~ 50 Hz/60 Hz

Power Consumption 20 W

Dimensions (W x H x D) Satellite: Approx. 110 (W) mm x 201 (H) mm x 115 (D) mm

Subwoofer: 264 (W) mm x 370 (H) mm x 323 (D) mm

Net Weight Main Set : Approx. 5.44 kg Speaker (1EA) : Approx. 0.64 kg

Operating Temperature 0 °C to 35 °C

Connectivity 3,5mm stereo jack-male input jack

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

Impedance Subwoofer: 6 (Ω)

Satellite: 8 (Ω)

Frequency response Subwoofer: 55 Hz ~ 104 Hz Satellite: 40 Hz ≤ 20 kHz

Total Max. power 70 W (THD : 10 %)

Signal to noise ratio 75 dB

• Design and specifications are subject to change without notice.

1-11

1-12

SECTION 2

CABINET & MAIN CHASSIS

CONTENTS

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

1. SUBWOOFER SECTION .......................................................................................................................... 2-3

2. SPEAKER SECTION ................................................................................................................................ 2-5

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

2-1

2-2

A40

300

MAIN

SMPS

261

512

511

513

260

A47

507

CABLE1

A46

A45

825

EXPLODED VIEWS

1. SUBWOOFER SECTION

NOTES) THE EXCLAMATION POINT WITHIN AN

EQUILATERAL TRIANGLE IS INTENDED TO ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY INFORMATION IN SERVICE LITERATURE.

2. SPEAKER SECTION

A60L (RCA: White)

A60R (RCA: Red)

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