Page 1
CAR CD/MP3/WMA Receiver SERVICE MANUAL CAUTION BEFORE SERVICING THE UNIT, READ THE “SAFETY PRECAUTIONS” IN THIS MANUAL. MODELS:LAC-M7600R/LAC-M7600 P/N : AFN30086098 APRIL, 2006...
SECTION 1. SUMMARY ❏ SERVICING PRECAUTIONS ❶ Always disconnect the power source before: 1) Removing or reinstalling any component, circuit board, module or any other instrument assembly. 2) Disconnecting or reconnecting any instrument electrical plug or other electrical connection. 3) Connecting a test substitute in parallel with an electrolytic capacitor in the instrument. CAUTION: A wrong part substitution or incorrect polarity installation of electrolytic capacitors may result in an explosion hazard.
❏ 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.
❏ SPECIFICATIONS MP3/WMA Disc compatibility with this unit is limited as follows: 1. Sampling Frequency/8 - 48kHz (MP3) 22.05 - 48kHz (WMA) 2. Bit rate/within 8 - 320kbps (include VBR) (MP3) 32 - 320kbps (WMA) 3. CD-R/CD-RW file system should be “ISO 9660” 4.
SECTION 2. ELECTRICAL ❏ ELECTRICAL TROUBLESHOOTING GUIDE 1. No Power. Any Key power on. Check power supply circuitry. Q722, Q727, IC702, Q723, Q805, Is power turnd on? Q806, Q720, Q719, IC701 Check loading supply circuitry. DISC loading? Q701, Q702, Q703, Q704, PN503, Q503, IC508 Check laser circuitry.
Page 7
2. VFD light abnornal. Any Key power on. (without DISC) Power supply circuitry defective. Check voltage in the power Do display VFD then light? Q601, Q602, IC602, T901 supply circuitry. Is u-com IC102 reset circuit • Reset circuit defective. normal? IC102-74Pin IC903 Surrounding circuit defective.
Page 8
3. Initial reading is not carried out. Defective Check the Voltage change of Slide motor moves connector CN503 PN502 Pin1 (6.4~6.8V) (With disc) Check the Voltage IC506 Defective IC506 Pin23 (1.4V~1.8V) Spindle motor turns Check the Data transmission WAVEFORM #1 from IC510 (58, 72, 70) Defective MICOM DSP WAVEFORM #5...
When laser does not light. Is “2.4V~3.4V” applied to pin42 of IC506? ➀ 3.4V ➁ 2.4V) Did pickup return to Is data transferred Defective MICOM (IC510) innermost circular? from IC510 Does voltage appear at Defective IC506. IC504 Pin 13, 14? Defective slide motor and/or connector.
Page 10
When laser light. Laser lights Check the signal FOCUS Defective IC506 SEARCH of IC506 Pin25 WAVEFORM #3 Check the signal of IC504 Pin 15, 16 Defective IC506 WAVEFORM #3 Degraded laser diode Defective PICK-UP When SPINDLE motor dose not turn Check the change for SPDO Voltage Defective IC506...
❏ WAVEFORMS OF MAJOR CHECK POINT #1. SPINDLE DRIVE AND MOTOR WAVEFORM #2. RF WAVEFORM IC501(21), IC502(12) during TOC reading IC506(45), IC506(49) during TOC reading #3. FOCUS DRIVE AND MOTOR WAVEFORM IC506(25), IC504(15) • When focus search failed or there is no disc on tray •...
Page 24
3) Pin Function Pin no. Symbol Function Adress signal output for DRAM11 Adress signal output for DRAM9 Adress signal output for DRAM8 Adress signal output for DRAM7 Adress signal output for DRAM6 Adress signal output for DRAM5 Adress signal output for DRAM4 Writing enable signal output for DRAM NCAS CAS control signal output for DRAM...