1. MAIN, FRONT & TUNER PART................................................................................................................................2-1
2. CD PART.....................................................................................................................................................................2-4
INTERNAL BLOCK DIAGRAM OF ICs......................................................................................................................2-10
1. MAIN CIRCUIT DIAGRAM ......................................................................................................................................2-21
3. FRONT CIRCUIT DIAGRAM ..................................................................................................................................2-25
4. AUX CIRCUIT DIAGRAM........................................................................................................................................2-27
1. MAIN P.C.BOARD ....................................................................................................................................................2-29
3. FRONT P.C.BOARD ................................................................................................................................................2-34
4. AUX P.C.BOARD......................................................................................................................................................2-35
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.
2. Do not defeat any plug/socket B+ voltage interlocks with which instruments covered by this service
manual might be equipped.
3. Do not apply power to this instrument and or any of its electrical assemblies unless all solid-state
device heat sinks are correctly installed.
4. Always connect a test instrument’s ground lead to the instrument chassis ground before connecting
the test instrument positive lead. Always remove the test instrument ground lead last.
1) The service precautions are indicated or printed on the cabinet, chassis or components. When servicing,
follow the printed or indicated service precautions and service materials.
2) The Components used in the unit have a specified conflammability and dielectric strength. When replacing
any components, use components which have the same ratings. Components marked in the circuit diagram
are important for safety or for the characteristics of the unit. Always replace with the exact components.
3) An insulation tube or tape is sometimes used and some components are raised above the printed writing
board for safety. The internal wiring is sometimes clamped to prevent contact with heating components.
Install them as they were.
4) After servicing always check that the removed screws, components and wiring have been installed correctly
and that the portion around the service part has not been damaged. Further check the insulation between
the blades of attachment plug and accessible conductive parts.
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 know 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
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 ARROWHEAD 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 INTENED TO
ALERT THE SERVICE PERSONNEL TO THE PRESENCE OF IMPORTANT SAFETY
INFORMATION IN SERVICE LITERATURE.
Output Power50W x 4CH (Max.)
Power SourceDC 12V
Speaker impedance4Ω
Ground SystemNegative
Dimensions (W x H x D)180 x 51 x 171mm (Without Control Panel)
Net Weight2.0kg
Checked the Back up Vdd, Gnd.CN801(16,15)
Checked the Micom Back Up Vdd.IC301(14), D307, IC401(30,47,50,99,100)
Checked the Micom Ground.IC401(20,51,97,98)
Checked the Reset.IC402, IC401(90)
Checked the X-tal.X401, X402
Checked the ACC in. Q301, Q302, IC401(38), CN801(14)
Checked the detachable switch.SW401, IC401(73)
Checked the flipdown Detector.CN901(19), IC401(74)
Checked the Key line.IC401(52,53)
2 Not available RemoconChecked the Remocon Sens Vdd.CN901(14), Q316, Q317, D307
Checked the Remocon Sens line. RM901, IC401(5)
3 Not available to Volume controlChecked the Encoder Volume.SW901, IC401(40,41)
4 Not available to Key ControlChecked Tact switch.SW902 ~ SW918
Checked Key line.IC410(52,53)
5 No soundChecked the E-VR Vdd.IC301(10), IC601(16)
Checked the E-VR Ground.IC601(1,22)
Checked the E-VR control.IC601(22,23), IC401(1,2)
Checked the E-VR Signal in/out.IC601(3,5,6,7,10,11)
IC601(12,13,14,15)
Checked the E-VR Mute ControlIC601(19), IC401(6)
* Power ICChecked the Power IC Vdd.IC801(6,20)
: Refer to next pageChecked the Power IC Ground. IC801(1,2,8,13,18,24)
Checked the Power IC Control.IC801(4, 22), IC401(3,10)
Checked the Power IC Signal in/out.IC801(11,12,14,15)
IC801(3,5,7,9,17,19,21,23)
Checked the Power IC Mute.IC801(22)
Checked the Power IC Standby.IC801(4)
Checked the Power IC Ripple.IC801(10)
Checked the Main Connector.CN801(1,2,3,4,8,9,12,13)
6 No Line out signalChecked the E-VR Vdd.IC301(10), IC601(16)
Checked the E-VR Ground.IC601(1,22)
Checked the E-VR control.IC601(20,21), IC401(1,2)
Checked the E-VR Signal in/out.IC601(3,5,6,7,10,11)
IC601(12,13,14,15)
Checked the Line out Mute circuitQ705, IC401(48)
Check the Line out JackCN703
8 Heard Pop NoiseChecked the Mute Control.IC601(19), IC801(4,22), IC401(3,6,10)
Checked the AF Mute.TU101(19), IC401(4)
9 Not avaliable to Telephone MuteChecked the telephone Mute Control.CN801(5), Q305, Q306, IC401(62)
Checked the Mute Control.IC601(19), IC801(4,22), IC401(3,6,10)
10 Not avaliable to ANT(Motor Type) Control Checked the ANT Control.IC301(12,13), IC401(87)
11 Not avaliable to RemoteChecked the Remote control.CN801(6), IC402(1,2,4), Q308, Q309
(External AMP)IC401(63,64)
12 No output Beep sound.Checked the Beep Control.IC401(80)
1 No Display or Checked the LCD DRV Vdd.Q322, Q316, Q317
Some Display is brokenIC901(58,59)
Checked the LCD DRV Ground.IC901(60)
Checked the LCD DRV OSC.IC901(61)
Checked the LCD DRV control.IC401(75,79,85,86),
IC901(57,62,63,64)
Checked the LCD DRV to LCD Pattern.
2 No LCD Lighting orChecked the LCD Lighting VDD.Q319, Q320, Q322, IC301(4,9)
Color is differentIC401(64)
Checked the LED.LD930, LD931
3 Not avaliable to LCD LightingChecked the LCD Lighting Control.CN801(11), Q303, Q304, Q321,
controlIC401(58)
Checked the LED.LD930, LD931
4 No Key LightingChecked the LED Lighting Vdd.IC301(4,9), IC401(64)
Checked the LED.LD901 ~ LD923
5 Don't moved Level barChecked the Level Meter control.IC401(54,57)
6 Not avaliable to Dimmer controlChekced the Dimmer control.CN801(11), Q303, Q304, IC301(4,9)
IC901(1 ~ 55)
NoSymptomCheck PointLocation No.
TUNER FUNCTION
1 Not available to TunerChecked the Tuner Vdd.TU101(4,16), IC301(10), IC401(39)
Q350, Q351
Checked the Tuner Ground.TU101(3, 5,10,17)
Checked the PLL data.TU101(11,12,13,14,15)
IC401(67,68,44,45,46)
Checked the RF signal in.TU101(1, 2)
Checked the S-Meter control.TU101(7)
Checked the SD & ST IND.TU101(6)
2 Tuner no soundChecked the Tuner Signal out.TU101(8,9), IC601(6,7)
Checked the AF mute.TU101(19), IC401(4)
3 Not available to RDSChecked the RDS data.TU101(20,21), IC401(65,83)