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Internal Use Only Website http://biz.lgservice.com Mini Hi-Fi System SERVICE MANUAL MODEL: CM8440 (CM8440, CMS8440F/W) CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. P/NO : AFN76932780 JANUARY, 2015...
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CONTENTS SECTION 1 ..GENERAL SECTION 2 ..CABINET & MAIN CHASSIS SECTION 3 ..ELECTRICAL SECTION 4 ..REPLACEMENT PARTS LIST...
SERVICING PRECAUTIONS 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. Storage in conductive bag Drop impact 2.
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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.
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.
HIDDEN KEY MODE Push both Front key and RCU key to activate it for 5 seconds. 1. Disc Lock On/Off (CD Function Only Active) Front Key : STOP RCU Key : STOP 2. Check Version and Option code ...
SERVICE INFORMATION FOR EEPROM POWER ON It is possible at any function. FLD “NO DISC” status (ex. It is possible at FLD “NO USB” status, too.) This is an example. Remote control ‘ ’ + Front ‘STOP’ DETECT NEW EEPROM push same timing during 5 seconds.
PROGRAM DOWNLOAD & UPDATE GUIDE 1. AUDIO PROGRAM Download program file name must be MICOM_CM8540_1311010_0x4D3F.HEX If security program (Water Wall) is activated on your 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.
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2. CD PROGRAM Download program file name must be HG480_CM8540_1401231.bin If security program (Water Wall) is activated on your 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.
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3. DEMO PROGRAM Download program file name must be DEMO_DAT.bin If security program (Water Wall) is activated on your 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.
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4. EQ PROGRAM Download program file name must be EQ_PRG_CM8440_201401110_D2E9.BIN If security program (Water Wall) is activated on your 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.
SPECIFICATIONS • GENERAL Power requirements Refer to the main label. Power consumption Refer to the main label. Dimensions (W x H x D) (290 x 349 x 370) mm Net Weight (Approx.) 5.9 kg Operating temperature 5 °C to 35 °C (41 °F to 95 °F) Operating humidity 60 % Bus Power Supply...
EXPLODED VIEWS 1. CABINET AND MAIN FRAME SECTION (CM8440) 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. CABLE1 FRONT CABLE2 SMPS CABLE3 NFC Tag MIC &...
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SECTION 3 ELECTRICAL CONTENTS ONE POINT REPAIR GUIDE ..........................3-2 1. NO POWER ............................3-2 2. NO BOOTING WHEN POWER ON THE SET ..................3-4 3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET ..............3-5 4. NO BOOTING IN CD/USB FUNCTION ....................3-6 5.
ONE POINT REPAIR GUIDE 1. NO POWER If the unit doesn’t work by no power problem, repair the set according to the following guide. 1-1. FUSE / BRIDGE DIODE / THERMISTOR 1-1-1. Solution Please check and replace F901, BD901, TH900, TH901 on SMPS board. 1-1-2.
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ONE POINT REPAIR GUIDE NO POWER If the unit doesn’t work by no ±PVDD problem, repair the set according to the following guide. 1-2. NO AMP POWER 1-2-1. Solution Please check and replace F911, Q905, Q906 on SMPS board. 1-2-2. How to troubleshoot (Countermeasure) 1) Check if the fuse F901 is open or short-circuit.
ONE POINT REPAIR GUIDE 2. NO BOOTING WHEN POWER ON THE SET The set doesn’t work when press the power button on the front board or the remote control. 2-1. MICOM (IC501) 2-1-1. Solution Please check and replace IC501 on MAIN board. 2-1-2.
ONE POINT REPAIR GUIDE 3. VFD IS NOT DISPLAYED WHEN POWER ON THE SET When power on the set, any icons or characters on VFD are not displayed. 3-1. VFD (DIG300) 3-1-1. Solution Please check and replace DIG300 on FRONT board. 3-1-2.
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ONE POINT REPAIR GUIDE 4. NO BOOTING IN CD/USB FUNCTION After you turn on power key and displayed message in the following order (HELLO --> VOL XX --> CD or USB) on VFD, it will not display other message on VFD, and it will not boot-up normally. 4-1.
ONE POINT REPAIR GUIDE NO BOOTING IN CD/USB FUNCTION After you turn on power key and displayed message in the following order (HELLO --> VOL XX --> CD or USB) on VFD, it will not display other message on VFD, and it will not boot-up normally. 4-2.
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ONE POINT REPAIR GUIDE NO BOOTING IN CD/USB FUNCTION After you turn on power key and displayed message in the following order (HELLO --> VOL XX --> CD or USB) on VFD, it will not display other message on VFD, and it will not boot-up normally. 4-3.
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ONE POINT REPAIR GUIDE NO BOOTING IN CD/USB FUNCTION After you turn on power key and displayed message in the following order (HELLO --> VOL XX --> CD or USB) on VFD, it will not display other message on VFD, and it will not boot-up normally. 4-4.
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ONE POINT REPAIR GUIDE NO BOOTING IN CD/USB FUNCTION After you turn on power key and displayed message in the following order (HELLO --> VOL XX --> CD or USB) on VFD, it will not display other message on VFD, and it will not boot-up normally. 4-5.
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ONE POINT REPAIR GUIDE 5. NO OPERATION OF MD (DRIVING THE SERVO MOTORS) When no sound output in the CD function, you can not listen to music reading data from a CD disc if the servo motors in MD don’t work. This step is for checking the SPINDLE MOTOR among them.
ONE POINT REPAIR GUIDE NO OPERATION OF MD (DRIVING THE SERVO MOTORS) When no sound output in the CD function, you can not listen to music reading data from a CD disc if the servo motors in MD don’t work. This step is for checking the SLED MOTOR among them.
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ONE POINT REPAIR GUIDE NO OPERATION OF MD (DRIVING THE SERVO MOTORS) When no sound output in the CD function, you can not listen to music reading data from a CD disc if the servo motors in MD don’t work. This step is for checking the TRAY OPEN/ CLOSE MOTOR among them.
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ONE POINT REPAIR GUIDE NO OPERATION OF MD (DRIVING THE SERVO MOTORS) When no sound output in the CD function, you can not listen to music reading data from a CD disc if the pickup module in MD doesn’t work. This step is for checking the LASER TRACKING ACTUATOR.
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ONE POINT REPAIR GUIDE NO OPERATION OF MD (DRIVING THE SERVO MOTORS) When no sound output in the CD function, you can not listen to music reading data from a CD disc if the pickup module in MD doesn’t work. This step is for checking the LASER FOCUSING ACTUATOR.
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ONE POINT REPAIR GUIDE 6. NO SOUND There is no sound output in the USB FUNCTION, repair the set according to the following guide. 6-1. IN THE USB FUNCTION 6-1-1. Solution Please check and replace IC501 on MAIN board & IC300 on USB board. 6-1-2.
ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the AUX FUNCTION, repair the set according to the fol- lowing guide. 6-2. IN THE AUX FUNCTION 6-2-1. Solution Please check and replace IC202 on MAIN board. 6-2-2. How to troubleshoot (Countermeasure) 1) Check AUX_L/R signals to IC202 (Pin7, 8).
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ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the PORT. IN FUNCTION, repair the set according to the following guide. 6-3. IN THE PORT. IN FUNCTION 6-3-1. Solution Please check and replace IC202 on MAIN board. 6-3-2.
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ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the TUNER FUNCTION, repair the set according to the following guide. 6-4. IN THE TUNER FUNCTION 6-4-1. Solution Please check and replace IC202, TU500 on MAIN board. 6-4-2. How to troubleshoot (Countermeasure) 1) Check if TUNER_LR is entered from Pin1 &...
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ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the MIC IN FUNCTION, repair the set according to the following guide. 6-5. IN THE MIC IN FUNCTION 6-5-1. Solution Please check and replace IC508 on Main Board or ICM101 on MIC board. 6-5-2.
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ONE POINT REPAIR GUIDE NO SOUND There is no sound output in the BLUETOOTH FUNCTION, repair the set according to the following guide. 6-6. IN THE BLUETOOTH FUNCTION 6-6-1. Solution Please check and replace IC501 on MAIN board and Bluetooth module on front panel. 6-6-2.
ONE POINT REPAIR GUIDE 7. AUDIO OUTPUT IS SMALL OR NO AUDIO OUTPUT Audio signal output is small or not. when you power on the Middle Power Mini System. 7-1. IC700 ~ IC705 7-1-1. Solution Please check and replace IC700 ~ IC705 on MAIN board. 7-1-2.
ONE POINT REPAIR GUIDE 8. NO POWER ON (STANDBY LED IS BLINKING) It doesn’t turn on, and blinks standby LED(Red). 8-1. AMP FETs 8-1-1. Solution Please check and replace Q705 ~ Q708, Q711 ~ Q718 on MAIN board. 8-1-2. How to troubleshoot (Countermeasure) 1) This symptom occurs, when DC protection is detected.
ONE POINT REPAIR GUIDE 9. SPEAKER NO AUDIO Speaker No Audio 9-1. AMP IC 9-1-1. Solution Please check and replace IC700 ~ IC705 on MAIN board. 9-1-2. How to troubleshoot (Countermeasure) 1) Check supply voltage of AMP(CN110) & PWM signal Normal Supply voltage and signal ...
ELECTRICAL TROUBLESHOOTING GUIDE 1. POWER SUPPLY ON SMPS BOARD No output 5.6 VA Replace F901 (same fuse). F901 normal? Replace BD901. BD901 normal? Is the VCC D960, D961 normal? (11 V ~ 25 V) supplied to IC901 Pin4? Power line of MAIN PCB is short. Check or replace D960, D961.
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ELECTRICAL TROUBLESHOOTING GUIDE No -5 V Is the R965 normal? Check or replace R965 / D959. VCC -7 VA supplied to IC953 Pin2? Check or replace Q951. Is there ‘H’ signal at Q953 Check P_CTL from μ-com. Base? Check or replace Q953, Q957. Or check line of MAIN PCB is short or not.
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ELECTRICAL TROUBLESHOOTING GUIDE No output AMP gate line Is the VCC R952 normal? 13 VA supplied to IC952 Check or replace R952. Pin1 to Pin3? Check and replace IC952. Check or replace D951, D952. Or check line of MAIN PCB is short or not. 3-27...
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ELECTRICAL TROUBLESHOOTING GUIDE No AMP output Is the PFC P.CTL OK? C904, C905 voltage Check PFC P.CTL from μ-com. about 380 V? Is the VCC 12 V supplied to Replace D908, Q955, PC903. IC904 Pin16? Check or replace IC904, Q907 ~ Q910. AMP P.CTL F911 normal? Check AMP P.CTL from μ-com.
ELECTRICAL TROUBLESHOOTING GUIDE 2. SYSTEM PART Power on. CN301 “HELLO” cable connection Display on FLD Check 17p FFC cable. CN301 Pin1, 3, 5 Check SMPS board. power OK? CN301 Pin9 ~ 11 data signal Check MAIN board. Q301, 303, 304 Replace DIG301.
ELECTRICAL TROUBLESHOOTING GUIDE 3. NO AUDIO PART CD FUNCTION Is motor_open/ close OK? LOAD +, - OK? disc insert? (IC408 Pin6, 7) Check IC501. Is motor impedance Check Loading motor. about 12 Ω? Check IC408. Focusing/ OPU driving Tracking/ Sled signal Disc reading OK? (Focusing &...
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ELECTRICAL TROUBLESHOOTING GUIDE USB play IC300 When insert USB, USB power +5 VU Replace IC300. IC501 PinU7,U8,A7,A8 USB_D signal OK? IC202 Pin7, 8 AUX input signal Check audio cable. IC202 Check IC501. Pin42,43,44 I2S input signal IC202 Pin41 Replace IC202. ADC/MIC_data output signal 3-31...
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ELECTRICAL TROUBLESHOOTING GUIDE POT. IN IC202 Pin21,22 POT. IN input signal Check MIC board. IC202 Check IC501. Pin42,43,44 I2S input signal IC202 Pin41 Replace IC202. ADC/MIC_data output signal TUNER TU500 IC202 TUNER_L/R output Pin23,24 TUNER_L/R input Check +3.3 V of TU500. signal OK? signal OK? IC202...
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ELECTRICAL TROUBLESHOOTING GUIDE IC501 Pin D1,D2,E1 I2S clock signal Check IC501. IC501 Pin E2 I2S data signal Check IC501. IC600 Replace IC600. PWM data output signal 3-33...
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ELECTRICAL TROUBLESHOOTING GUIDE Pin26,27,31,32 Pin28,29,35,36 of IC600, SWL/SWR± signal of IC600, FL/FR± signal Check IC600. Check IC600. IC601, 602 IC603,604 FL/FR audio signal SWL/SWR audio signal Check IC601, IC602. Check IC603, IC604. Pin13 of Pin13 of IC702,IC703,IC706,IC708 IC700,IC701,IC704,IC705 SWL/SWR audio signal FL/FR audio signal Check Check...
BLOCK DIAGRAMS 1. SMPS BLOCK DIAGRAM MAIN SMPS (STR-2A153) 4.5V FL(+/ -) Flyback MAIN OPAMP - 5V TRANS u-com / BT PFC Out 5.6VA USB / MPEG (380V) Motor Drive PFC IC FAN/LED/ Mic (R2A20112A) Totem pole 600V On/Off Interleaved On/Off Gate P-CTRL...
BE MODIFIED OR ALTERED WITHOUT PERMISSION FROM THE ACTUAL CIRCUIT USED. THIS WAY, 1. SMPS - POWER #1 CIRCUIT DIAGRAM FROM THE LG CORPORATION. ALL COMPONENTS IMPLEMENTATION OF THE LATEST SAFETY AND SHOULD BE REPLACED ONLY WITH TYPES PERFORMANCE IMPROVEMENT CHANGES INTO IDENTICAL TO THOSE IN THE ORIGINAL CIRCUIT.
2. SMPS - POWER #2 CIRCUIT DIAGRAM Warning Parts that are shaded are critical with respect to risk of fire or electrical shock. SMPS #2 EAX65367301_18.1.6_SMPS_SD_2 2014. 01. 25 3-49 3-50...