XR-4880 SERVICE MANUAL AEP Model UK Model Photo: XR-4880 Model Name Using Similar Mechanism XR-C6100R Tape Transport Mechanism Type MG-25F-136 SPECIFICATIONS FM/MW/LW CASSETTE CAR STEREO MICROFILM SECTION 6 DIAGRAMS 22 21 20 18 19 17 16 15 14 13 + AMP MOTOR DRIVE CIRCUIT CONTROL CIRCUIT IN2 4 VCC AUXIN2 DIREF LINEOUT2 29 28 27 26 25 24 9 OUT1 8 NC 7 OUT2 AMP – + 4BIT SWALLOW COUNTER T2 REGULATOR 6 P-GND SEEK/RECP PBFB2 31 PBRIN2 32 MS MODE X1 19 DRSW TAPE/AUX 18 TAPESW 17 INSW F2 TAPE EQ PBFIN2 34 + PRESCALLER 20 MSMODE NR BIAS PBREF2 33 SEEK/RECP + – – + S-GND 5 AMP 23 22 21 24dB 120µ/70µ BUFFER – + MSSW TAPEIN2 30 BUFFER IN1 3 VDD GND 10 NC PBOUT2 LB1930M-TLM PBEQ2 VCC 1 NC 2 IFC VDD FM IN AM IN D-GND FM CP OUT VT AM CP OUT VCC REG A-GND XI 24 23 IC351 CXA2509AQ-T4 NC IC301 IC21 TB2118F (EL) NC • IC Block Diagrams – MAIN Board – 16 NC FWD/RVS PHASE COMPARATOR SIG VCT 35 PBGND 36 12BIT PROGRAMMABLE COUNTER REF + LPF + – 14 MSOUT PBFIN1 37 40BIT SHIFT REGISTER F3 F1 PBREF1 38 18BIT 13 DGND X1 PBRIN1 39 PBFB1 40 22BIT 18BIT ON/OFF MS ON/ 15 NC OFF DETECT VCC 20BIT IF COUNTER REFERENCE DIVIDER 12 MSTC + – 11 G1FB – + OSCILLATOR VCT T1 OUT-1 VDD2 7 8 9 10 G2FB I/O-1 I/O-2 6 BA3918-V2 28 27 26 25 24 23 FRONT SIDE SELECTOR VOLUME CONTROL CIRCUIT SOFT MUTE TREBLE/ BASS CONTROL CIRCUIT FRONT FADER VOICE BANDPASS HP OVER VOLTAGE PROTECT 22 OUT FL – + LP FRONT FADER 21 OUT FR REAR FADER 20 OUT RL REAR FADER 19 OUT RR INPUT GAIN LOUDNESS CONTROL CIRCUIT SUBWOOFER LP BEEP NC VDD AMP VCC IC751 8 9 10 11 12 GND 7 FM 6 AM 5 ANT 2 3 4 COM 1 MODE2 MODE1 STB COMPANDER REAR SIDE SELECTOR INPUT MULTIPLEXER & MIXING STAGE LOUDNESS CONTROL CIRCUIT REGULATOR + – INPUT GAIN & AUTO ZERO SE3L SE3R MUTE SDA SCL PAUSE + – 1 2 3 4 5 6 7 8 9 10 11 12 13 4 5 TDA7462D PAUSE DETECT SE1L SE1R MD+ MD– CDL+ CDL– CDR– CDR+ PDR PDGND PDL SE2L SE2R 3 + – IC331 2 NC SR IC661 1 NC 12 LINEOUT1 10 11 MSLPF 9 TAPEIN1 AUXIN1 8 VCC 7 24dB PBOUT1 3 4 5 6 120µ/70µ PBEQ1 2 OUT-2 1 CE DIN CK DOUT OUTPUT PORT OSC I/O PORT XO SERIAL INTERFACE VDD2 BUFFER TDA7385 FADER 18 SUBOUT+ SUBWOOFER OUT 17 SUBOUT– SDA IIC BUS SCL POWER SUPPLY CREF 14 – 17 – 16 VDD 15 GND 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 TAB PW-GND OUT2– ST-BY OUT2+ Vcc1 OUT1– PW-GND1 OUT1+ SVR IN1 IN2 S-GND IN4 IN3 AC-GND OUT3+ PW-GND3 OUT3– Vcc2 OUT4+ MUTE OUT4– PW-GND4 DIAGNOSTICS OUT DIGITAL CONTROL CIRCUIT – 18 – XR-4880 6-2. SCHEMATIC DIAGRAM — MAIN (1/2) SECTION — • Refer to page 17 for IC Block Diagrams. • Refer to page 29 for IC Pin Function Description. FAE342-E01 • Waveforms 1 2.8Vp-p (FL) 18.432MHz IC501 !™ OSC2 2 5.0Vp-p A (OFF) → B (ON) 32.768MHz IC501 !§ XO Note on Schematic Diagram: • All capacitors are in µF unless otherwise noted. pF: µµF 50 WV or less are not indicated except for electrolytics and tantalums. • All resistors are in Ω and 1/4 W or less unless otherwise specified. ¢ • : internal component. • C : panel designation. • U : B+ Line. • Power voltage is dc 14.4V and fed with regulated dc power supply from ACC and BATT cords. • Voltage and waveforms are dc with respect to ground under no-signal conditions. no mark : FM < > : TAPE PLAYBACK : Impossible to measure ∗ • Voltages are taken with a VOM (Input impedance 10 MΩ). Voltage variations may be noted due to normal production tolerances. • Waveforms are taken with a oscilloscope. Voltage variations may be noted due to normal production tolerances. • Circled numbers refer to waveforms. • Signal path. F : FM f : AM (MW) E : TAPE PLAYBACK (Page 23, 24) – 21 – – 22 – XR-4880 6-3. SCHEMATIC DIAGRAM — MAIN (2/2) SECTION — • Refer to page 17 for IC Block Diagrams. • Refer to page 19 for Printed Wiring Board. (Page 21, 22) Note on Schematic Diagram: • All capacitors are in µF unless otherwise noted. pF: µµF 50 WV or less are not indicated except for electrolytics and tantalums. • All resistors are in Ω and 1/4 W or less unless otherwise specified. ¢ : internal component. • • C : panel designation. • U : B+ Line. • Power voltage is dc 14.4V and fed with regulated dc power supply from ACC and BATT cords. • Voltage and waveforms are dc with respect to ground under no-signal conditions. no mark : FM < > : TAPE PLAYBACK : Impossible to measure ∗ • Voltages are taken with a VOM (Input impedance 10 MΩ). Voltage variations may be noted due to normal production tolerances. • Waveforms are taken with a oscilloscope. Voltage variations may be noted due to normal production tolerances. • Circled numbers refer to waveforms. • Signal path. F : FM f : AM (MW) E : TAPE PLAYBACK (Page 27) – 23 – – 24 – XR-4880 6-5. SCHEMATIC DIAGRAM — PANEL SECTION — • Refer to page 25 for Printed Wiring Board. (Page 23) Note on Schematic Diagram: • All capacitors are in µF unless otherwise noted. pF: µµF 50 WV or less are not indicated except for electrolytics and tantalums. • All resistors are in Ω and 1/4 W or less unless otherwise specified. ¢ • : internal component. • C : panel designation. • U : B+ Line. • Power voltage is dc 14.4V and fed with regulated dc power supply from ACC and BATT cords. • Voltage and waveforms are dc with respect to ground under no-signal conditions. no mark : FM < > : TAPE PLAYBACK : Impossible to measure ∗ • Voltages are taken with a VOM (Input impedance 10 MΩ). Voltage variations may be noted due to normal production tolerances. – 27 – • Waveforms are taken with a oscilloscope. Voltage variations may be noted due to normal production tolerances. • Circled numbers refer to waveforms. • Signal path. F : FM f : AM (MW) E : TAPE PLAYBACK – 28 – 6-6. IC PIN FUNCTION DESCRIPTION • IC501 MASTER U-COM (MN101C12GTC1) Pin No. 1 Pin Name VREF- I/O – Function Basic voltage (- side) of AD conversion input 2 VSM I FM/AM common signal meter A/D conversion input terminal 3 KEYIN1 I 4 KEYIN0 I 5 DBASS IN I Position detecting AD input terminal of D-BASS 6 DSTSEL I Terminal for setting to select the value of destination 7 FUNC-SEL I Function selecting (AD conversion) input 8 – O Not used KEY (AD conversion) input 9 RC-IN0 I Rotary commander (AD conversion) input 10 VREF+ I Basic voltage (+side) of AD conversion input 11 VDD – Power supply 12 OSC2 – 13 OSC1 – Radiator (18.432 MHz) connecting terminal 14 VSS – 15 XI – Ground 16 XO – 17 MMOD GND – Ground 18 RC-IN1 I Rotary commander shift input 19 SYSRST O SYSTEM RESET control output 20 BUSON O BUS ON control output 21 UNISO O Serial data output 22 UNISI I Serial data input 23 UNICKO O Serial clock output 24 UNICKI I Serial clock input 25 – O Not used 26 KEYACK I Key input acknowledge Sub clock (for clock) radiator (32 kHz) connecting terminal 27 NOSESW I Removing/attaching front panel detection input 28 BU-IN I BACK-UP detection input terminal 29 SIRCS I Remote control input 30 TELMUT I TELEPHONE MUTE detection input 31 TEST-IN I Test mode setting input terminal 32 RAMBU I Reset detection input of RAM 33 RESET I Reset input terminal 34 VOL-MUT O Electrical volume mute control output 35 BEEP O Control output for buzzer 36 AMPMUT O Power amplifier mute control output terminal 37 AMPON O Power amplifier STANDBY control terminal 38 PLL-CKD O PLL CLK output terminal 39 PLL-CE O PLL CE output terminal 40 PLL-SO O PLL DATA output terminal 41 PLL-SI I PLL DATA input terminal 42 LCD-SO O LCD serial data output 43 LCD-CE O LCD chip enable output terminal 44 LCD-CKO O LCD serial clock output 45 VOL-SIO O Electrical volume serial data output 46 – O Not used 47 VOL-CKD O Electrical volume serial data output 48 ACC-IN I Accessory power supply detection input 49 MUT O System MUTE control output – 29 – Pin No. Pin Name I/O Function 50 NCO O Not used 51 AMSON O “L” is output in AMS mode 52 N/R-OUT O FWD/REV control output 53 MTLON I/O Metal control input/output 54 TAPMUT O 55 DOLON I/O 56 57 to 75 Tape mute control output Dolby control input/output AMSIN I Input to detect existence of song during AMS mode NCO O Not used 76 ST 77 SD-IN I/O I 78 REIN 1 I 79 REIN 0 I 80 AD ON O Power supply control output of AD conversion 81 PW SEL I Power selection initialise 82 ILLON O Illumination power supply control output Input to detect rotation of reel table 83 REL I 84 POS3 I 85 POS2 I 86 POS0 I 87 POS1 I 88 LM LOD O 89 LM EJ O Combination stereo input and monaural output SIGNAL DETECTOR input terminal Rotary encoder input terminal Tape position signal detection input Loading motor control output (to a direction of loading) Loading motor control output (to a direction of ejection) TAPE power supply control output 90 TAPON O 91 CM ON O Capstan motor control signal output terminal of TAPE 92 PW ON O System power supply control output 93 FM ON O FM power supply control output terminal 94 TUNON O TUNER power supply control output terminal 95 96 to 99 100 When ‘on’ is output, “H” is output, otherwise when ‘off’ is output, “L” is output. DAVSS – Ground NCO O Not used DAVDD – Not used (Power supply for DA converter) – 30 –