Denon DN-730R User Manual

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DEMON

SERVICE MANUAL^

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MODEL

DN-730R

STEREO CASSETTE TAPE DECK

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— TABLE OF CONTENTS —

SPECIFICATIONS........................................................................................................................................................3

BLOCK DIAGRAM........................................................................................................................................................4

LEVEL DIAGRAM.........................................................................................................................................................5

DISASSEMBLY INSTRUCTIONS............................................................................................................................6~7 ADJUSTING AND CHECKING THE MECHANISM SECTION

ADJUSTING THE ELECTRICAL SECTIONS........................................................................................................9~10

NOTE FOR PARTS LIST............................................................................................................................................10

PARTS LIST OF 3U-2584 AUDIO METER UNIT................................................................................................. 11-13

PARTS LIST OF 3U-2063 POWER SUPPLY UNIT...................................................................................................13

PARTS LIST OF EXPLODED VIEW.......................................................................................................................... 14

EXPLODED VIEW......................................................................................................................................................15

EXPLODED VIEW OF CASSETTE MECHANISM.....................................................................................................16

PARTS LIST OF CASSETTE MECHANISM EXPLODED VIEW...............................................................................17

PARTS LIST OF PACKING & ACCESSORIES.........................................................................................................17

PACKING & ACCESSORIES.....................................................................................................................................17

P.W. BOARD OF 3U-2584 AUDIO/METER UNIT......................................................................................................18

P.W. BOARD OF 3U-2063 POWER SUPPLY UNIT..................................................................................................19

SEMICONDUCTORS............................................................................................................................................20-21

BUNDLE DIAGRAM...................................................................................................................................................21

WIRING DIAGRAM.....................................................................................................................................................22

SCHEMATIC DIAGRAM.............................................................................................................................................23

....................................................................................

NIPPON COLUMBIA CO.. LTD.

IÛN-730RI

i'SPECIFICATICMSIS

ICDN-ySORI

Type

Heads

Motors

Tape Speed Variable (PLAY) Fast Forward,

Rewind Time Flecording Bias Overall S/N Ratio

(at 3% THD Overall Frequency

Response Channel Separation Crosstalk Wow & Flutter Inputs

Line

Outputs

' Line

Headphone

Power supply Power Consumption Dimensions Weight Installation _

Vertical tape loading; 4-track 2-channel stereo cassette deck

Recording/playback head (amorphous) X 1 Erase head (Double-gap ferrite) X 1 Capstan (DC servo motor) X 1 Reel (DC motor) X 1

4.8 cm/sec. (FIX) Approx. ±12%

Approx. 110 sec. with a C-60 cassette Approx. 105 kHz

Dolby t NR on: more than 74 dB (CCIR/ARM)

25-19,000 Hz ±3 dB (at —20 dB, Metal tape) More than 40 dB (at 1 kHz) More than 65 dB (at 1 kHz)

0.055% WRMS (JIS method), ±0.14% w. peak

80 mV (—20 dBm) input level at maximum Input impedance: 50 kohm unbalanced

775 mV (0 dB) output level at maximum (with 47 kohm load, recorded level of 200 pwb/mm)

1.2 mW output level at maximum (optimum load impedance 8 ohm-1.2 kohm)

Voltage is shown on rating label

16 W

482 (W) X 134 (H) X 275 (D) mm

4.7 kg 19-inch rack mountable (3U)

Above specifications and design styling are subject to change for improvement.

Dolby noise reduction and HX Pro headroom extension manufactured under licence from Dolby Laboratories Licensing Corporation. HX Pro originated by Band & Olufsen. "DOLBY", the double-D symbol □□ and "HX PRO" are trademarks of Dolby Laboratories Licensing Corporation.

Best results will be obtained with use of DENOIM DX and HD Series cassette

tapes.

REC/PB MEAD

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JK301

0/2)

LINE IN LCM

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DOLBY NR SYSTEM iC

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-LEVEL DIAGRAM

PLAYBACK SYSTEM

TCC-130 IDOLBY B-Pi^PE

400 Hz 200 nwb/m

1CDN-730RI

RECORDING SYSTEM

INPUT FREQUENCY

400 Hz

-40

-50

-60

-70 -

REC PLAY FREQUENCY : 400H7

IDN-730RI

j DISASSEMBLY INSTRUCTIONS j

1. How to Remove the Front Panel

(1i Remove the four screws, (4 X 12. CBTS-P) in the side of the

top cover. Move the top cover to the rear and rise it to remove it.

(2) Press the eject knob, open the cassette box and remove the

cassette window as shown in the figure. .

Note: Handle the cassette window with care because it

can be scratched easily.

(3' Remove the three screws (3x10 CBTS-P) on top of the

front panel, the two hooks on the top, the three hooks on the bottom and pull the unit forward to detach it.

(3) Disconnect all lead connectors.

C Mechanism ( W151 (7P) — CN151 '

I Head wire — CN301

Head wire — CN302

Meter circuit board

Remove Volume Knob and Volume Knob (C).

(4)

Remove the four retaining screws (2 6 x 6 CBTS(Si)-Z) (3

(5)

X 10 CBTS(P)-B) holding the Mecha Bracket.

Remove the Hooks at the left and right of the f 'ont face of

(6)

the Front Esc. Ass'y, and the two hooks on the bottom. Front Ass'y can be removed towards the front.

I W131 (3P) - CN131

23PFFC-CB121 .

Audio circuit

board

2 hooks on the top of the front panet

m,...i. i. .... a

3 hooks on the bottom of the front panel

_ _____________0_

2. How to Remove the Front Escutcheon Ass'y

(1) Remove the top cover and front panel. (Refer to Step 1 ) (2) Remove the three retaining screws 3x10 CBTS-(P)-B

holding the Front Escutcheon at the front.

Hooks at left and right of Front Esc. Ass'y

3. How to Remove the Mec hanisms

Remove the four Mechanism retaining screws 3x10 CBTS(P)-B and lake out C Mechanism.

4. How to Remove the Meter Circuit Board

(1) Remove the top cover and the front panel. (Refer to section

1.)

(2) Remove the front esc. ass'y, (Refer to section 2.)

(3) If you remove the five binding screws (3x8 CBTS -P tight)

of the meter circuit board, and loosening the five hooks, the meter circuit board can be taken off. Note; When replacing the tact switch, check to make sure

that It is not floating above the circuit board. If it is floating, the switch will oe in the on condition when the set is assembled

Meter Circuit Board

5. How to Remove the Cassette Door

(1 ) Remove the MINIthA'I'JIPER'retaining screw J x 8 CBTS(P)-

B and take out thé MINI DAMPER,

(2) Hold the legs of the CASSETTE BOX folded inwards and

pull up to remove the CASSETTE BOX and BOX SPRING.

tDN-730RI

Front surface of Front Ass'y

6. How to Remove the Audio Circuit Board

(1) Remove the top cover and the front panel. (Refer to section

. 1.)

Remove the front esc. ass'y. (Refer to section 2.)

(21

Remove the connectors from the audio circuit boaid and

(3)

power supply circuit board.

Side of the Side of the Power supply CN901 — (7P) — CN901 audio circuit circuit board TBG board

' CONNECTOR

Note: • Almost all of the service repairs to the audio cir

cuit board can be performed by removing the bottom cover on the rear side of the chassis Only when it IS unavoidable should you refer to the removal method mentioned above.

• When reassembling, follow the procedures in the reverse order. However, if each of the various parts are not assembled properly in their respec tive position, the sel cannot be assembled in

somie cases. Therefore, check the work of each step carefully when assembling.

How to Remove the Power Supply Circuit Board

Remove the top cover and the front panel. (Refer to section

1 )

Remove the bushing that is fixing the power supply cord from the chassis. When the five screws (4x19 CBTS-P tight) (3x10

(3)

CBTS-P tight) that are holding the power transformer and chicuit board are removed, the power supply circuit board can be removed by raising it.

Cress.s

Remove the screw (3 x 10 CBTS-P tight) (3 xBCBTS-S

(4)

tight) that is holding down the 4P pin jack and circuit board. By removing the two catches (left and right) of the chassis holding down the circuit board in the directions of the arrows shown below, the audio circuit board can be pulled forward.

IE)N-730ni

ADJUSTING AND CHECKING THE

MECHANISM SECTION

1. Replacing-the Pinch Roller (36)

Before replacing the pjnch roller, clean the tape contact surface of the pinch roller and the capstan shaft. Most causes of poor tape transport can be traced to dirty pinch roller and capstan shaft. Remove the clips that press the pinch roller and pull the pinch roller forward to remove it. After replacing, run a padless C-90 tape to check for tape curls at the tape guide section of the head.

2. Checking the Pressure Force of the Pinch

Roller (36).

In the playback mgdej^hpok a spring weight opto the bracket at the center o* the pinch roller. After separating the pinch roller from the capstan siTaft, allow the pinch roller to contact the caps tan shaft again. Check to make sure the spring weight reads be tween 250 ~ 350 g when the pinch roller starts to rotate Replace the pinch roller (36) when it does not conform to the standard specification values.

Capstan shaft

4. Replacing the ERASE HEAD (15)

(1) Unscrew the erase head holding screws (53). (2) By unsoldering the HEAD W RES can be taken off the

mechanism unit.

(3) When the replacement is completed, secure the screws

with the screw lock.

white;

5. Checking the Take-up Torque

Load the cassette type torque meter (SONY TW21;1 1).

Check to make sure that the average torque meter reading is within 30-70 g-crn during playback. If it is not within this range, check the voltage (approx. 4V) of tha reel motor. If the voltage is

low, the torque will be weak: if it is high, the torque will be strong.

6. Checking the FF and REW Torques

Load the cassette type torque meter (SONY TW2231). Check to

make sure the torque meter indicates within 90—180 g-cm at the end of FF and REW.

7. Checking the Back Tension Torque During

Record/Playback

Load the cassette type torque meter (SONY TW21 11) : check

to make sure the torque meter reads between 2 —6 g-cm during

playback and that there is no unevenness.

If it is not within this range, replace the reel ass'y (5) or Washer.

3. Replacing the Record/Playback Head (14)

(1) How to remove the R/P HEAD.

1) Remove securing screw (1) and azimuth adjusting screw (1) from the record/playback head.

2) Remove the soldered head wire and disassemble the mechanical unit to remove the record/playback head.

(2) How to assemble the R/P HEAD.

Reverse the above 1 procedures for removing the R/P HEAD.

' Solder the HEAD WIRE according to the diagram,

mechanism (recording/play back head)

8. Checking the FF and REW Times

Load a C-60 cassette tape (DEMON GR-2/60): check to make sure the tape is fast forwarded or rewound within 110 sec onds. If it is not within this range, check sections 5 and 6.

9. Checking the Existence of a Cassette Housing and the Operation of the Erase Prevention, Metal and Chrome Switch

Confirm that the sensor arm properly detecting the tape t/pe de tection holes on the cassette housina.

+ 17 hidden pages