Page 1
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...
TABLE OF CONTENTS GENERAL Location of Controls ............3 Resetting the Unit ............4 Detaching the Front Panel ..........4 Setting the Clock ............. 4 Installation ............... 5 Connections ..............6 DISASSEMBLY ............8 ASSEMBLY OF MECHANISM DECK .... 10 MECHANICAL ADJUSTMENTS .......
Page 3
SECTION 1 This section is extracted from instruction manual. GENERAL – 3 –...
SECTION 2 DISASSEMBLY Note: Follow the disassembly procedure in the numerical order given. FRONT PANEL ASS’Y 1 Push the button (release). 2 Remove the front panel ass’y to the direction of the arrow A . COVER ASS’Y 3 Cover ass’y –...
Page 9
SUB PANEL, MECHANISM DECK (MG-25F-136) 5 Screw (PTT2.6 × 6) 3 Connector (CN351) 6 Mechanism deck (MG-25F-136) 4 Flexible flat cable (CN301) 2 Sub panel 1 Three screws (PTT2.6 × 8) 1 Three screws (PTT2.6 × 8) 5 Two screws (PTT 2.6 ×...
SECTION 3 ASSEMBLY OF MECHANISM DECK Note: Follow the assembly procedure in the numerical order given. 5 Fit projection on C part. HOUSING 7 Holder the hanger by bending the claw. 2 Install the hanger onto two claws of the housing. 1 Install the catch to the hanger.
Page 11
LEVER (LDG-A) / (LDG-B) Shaft A Shaft A Shaft B Shaft B Shaft C 1 Fit the lever (LDG-A) on shafts A – C and install it. 3 Type-E stop ring 2.0 2 Fit the lever (LDG-B) on shafts A and B and install it.
Page 12
GUIDE (C) 2 Guide (C) 1 Three claws MOUNTING POSITION OF CAPSTAN/REEL MOTOR (M901) 30 ° 3 Capstan/reel motor(M901) 2 Two precision screws (P 2 × 2) 1 Belt – 12 –...
SECTION 5 SECTION 4 ELECTRICAL ADJUSTMENTS MECHANICAL ADJUSTMENTS 1. Clean the following parts with a denatured-alcohol-moistened TEST MODE swab: This set have the test mode function. In the test mode, FM Auto playback head pinch roller Scan/Stop Level and MW Auto Scan/Stop Level adjustments can rubber belt capstan be performed easier than it in ordinary procedure.
FM Stereo Separation Adjustment TUNER SECTION 0 dB=1 µV Setting: [SOURCE] button: FM Cautions during repair FM RF signal When the tuner unit is defective, replace it by a new one be- level meter antenna jack (J1) generator cause its internal block is difficult to repair. 4 Ω...
Page 15
Auto Scan/Stop Level Adjustment Make this adjustment after "FM Auto Scan/Stop Level Adjustment". Setting: [SOURCE] [MODE] button: MW 30 Ω 15 pF 65 pF AM RF signal generator AM dummy antenna (50 Ω ) antenna jack (J1) Carrier frequency : 999 kHz 30% amplitude modulation by 1 kHz signal...
Page 16
Adjustment Location: —SET UPPER VIEW– Tape Speed Adjustment RV1 MW Auto Scan/Stop Level Adjustment RV2 FM Auto Scan/Stop Level Adjustment RV4 FM Stereo Separation Adjustment – 16 –...
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 2.8Vp-p (FL) 18.432MHz IC501 !™ OSC2 5.0Vp-p A (OFF) → B (ON) 32.768MHz...
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.
XR-4880 6-5. SCHEMATIC DIAGRAM — PANEL SECTION — • Refer to page 25 for Printed Wiring Board. (Page 23) Note on Schematic Diagram: • Power voltage is dc 14.4V and fed with regulated dc power • Waveforms are taken with a oscilloscope.
6-6. IC PIN FUNCTION DESCRIPTION • IC501 MASTER U-COM (MN101C12GTC1) Pin No. Pin Name Function VREF- – Basic voltage (- side) of AD conversion input FM/AM common signal meter A/D conversion input terminal KEYIN1 KEY (AD conversion) input KEYIN0 DBASS IN Position detecting AD input terminal of D-BASS DSTSEL Terminal for setting to select the value of destination...
Page 24
Pin No. Pin Name Function Not used AMSON “L” is output in AMS mode N/R-OUT FWD/REV control output MTLON Metal control input/output TAPMUT Tape mute control output DOLON Dolby control input/output AMSIN Input to detect existence of song during AMS mode 57 to 75 Not used Combination stereo input and monaural output...
SECTION 7 EXPLODED VIEWS NOTE: • The mechanical parts with no reference number in • -XX, -X mean standardized parts, so they may have the exploded views are not supplied. some difference from the original one. • Hardware (# mark) list and accessories and pack- •...
Page 26
(2) FRONT PANEL SECTION not supplied (KEY board) LCD901 Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark 3-030-838-11 BUTTON (RELEASE) * 61 3-030-839-01 SHEET (REFLECTOR) 3-030-832-11 LEVER (S/A) 3-932-475-01 SPRING (RELEASE) * 62 3-030-824-01 PLATE, LIGHT GUIDE 3-030-834-01 BUTTON (M/S) 1-694-508-11 CONDUCTIVE BOARD, CONNECTION 3-030-835-01 BUTTON (1-6)
Page 27
(3) MECHANISM DECK SECTION (MG-25F-136) HP901 M901 Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark A-3291-667-A CLUTCH (FR) ASSY 3-933-346-01 CATCHER 3-019-130-01 LEVER (LDG-A) 3-933-344-01 GUIDE (C) 3-019-131-01 LEVER (LDG-B) 3-014-798-01 SCREW (HEAD), SPECIAL 3-020-539-01 SPRING (LD-1), TENSION 3-364-151-01 WASHER 3-020-540-01 SPRING (LD-2), TENSION A-3301-267-A CHASSIS ASSY (G)
SECTION 8 ELECTRICAL PARTS LIST Note: • SEMICONDUCTORS • Due to standardization, replacements in the parts list When indicating parts by reference In each case, u: µ , for example: may be different from the parts specified in the number, please include the board diagrams or the components used on the set.
Page 29
MAIN Ref. No. Part No. Description Remark Ref. No. Part No. Description Remark R964 1-216-033-00 METAL CHIP 1/10W 1-163-017-00 CERAMIC CHIP 0.0047uF 5% 1-163-809-11 CERAMIC CHIP 0.047uF R965 1-216-037-00 METAL CHIP 1/10W R966 1-216-033-00 METAL CHIP 1/10W 1-109-982-11 CERAMIC CHIP R967 1-216-037-00 METAL CHIP 1/10W...