Denon DN-730R Service Manual

IDENON

SERVICE MANUA

MODEL DN-730R

STEREO CASSE'I-I'E TAPE DECK

-- TABLE OF CONTENTS --

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

BLOCK DIAGRAM ......................................................................................................................................................... J,

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

DISASSEMBLY INSTRUCTIONS ........................................................................................................................... 6-7

ADJUSTING AND CHECKING THE MECHANISM SECTION .................................................................................. 3

ADJLISTING THE ELECTRICAL SECTIONS ....................................................................................................... 9-- 10

NOTE FOR PARTS LIST ........................................................................................................................................... l'D

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 CASSEq-I-E MECHANISM .................................................................................................... 16

PARTS LIST OF CASSEqq-E MECHANISM EXPLODED VIEW ............................................................................ 17

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

PACKING & ACCESSORIES ..................................................................................................................................... t7

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

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

SEMJCONDUCTORS ........................................................................................................................................... 20-21

BUNDLE DIAGRAM .................................................................................................................................................... 2:1

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

SCHEMATIC DIAGRAM ............................................................................................................................................. ,!'.3

NIPPON COLUMBIA CO.. LTD.

_ ON--730R

!'SPECIFICATIONSI

DN--730R I

Type

Heads

Motors

Tape Speed

Variable (PLAY) Fast Forward,

Rewind Time

Flecording Bias Overall S/N Ratio

(at 3% THD red,iF

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) × 1 Capstan (DC servo motor) × 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_ NR on" more than 74 dB (CCIR/ARM)

25N19,000 Hz 4:3 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 ohmN1.2 kohm) Voltage is shown on rating label

16W 482 (W) X 134 (H) ;< 275 (D) mm

4.7 kg 19-inch rack mountable (3U)

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

Dolb¥ noise reduction and HX Pro headroom extension manufactured under licence from bolby Laboratories Licensing Corporation. HX Pro originated by Band & Olufsen. "DOLBY", the double-D symbol 1313 and "HX PRO" are trademarks of Dolby Laboratories Licensing Corporation.

Best results will be obtained with use of DENON DX and HD Series cassette I tapes. 1

[ _BLOcK DI_A_G_B_A_M_

IiEVEL DIAGRAM j

PLAYBACK SYSTEM

TCC-130 IDOLBY B-TYPE

400 Hz 200 nw-b/m

DN-730R

PB HEAD PB EQ AMP PB GAiN

- - - (3) 7

TESI A_=

400_'z -- !' (2)

'J II .__'-'r:_ [ aT,o,

' dl + (RT20b

%? !

'°I

, -20_

-ac -i

60"

-704 -rob

_" _LAY BACK TCC-'30 400Hz 200nwbzm

RECORDING SYSTEM

INPUT FREQUENCY

400 Hz

IC302

DOLBY NR

SYSTEMIC

rC303

LINE MUTE HEA[',)PHONE AMP PHONES

T_?04 iC306 OUT

LINE _UTE ..... _+___,

I ÷TdB _HONES OUT LCAD ,B,Q

/J_-----Io_B L,NEO0,:,

OdB=775mV

LINE OUT

L KE INPUT

:N_:Z VOLUME

iNPUT FRE QUE'NC ,'

,pen) __ _OOk,z

L_n t

LE'_EL

÷';0 ]

-lo _

2OdB

40-

50 -_

-60"

-70

REC PLAY FREQUENCY : 400H'z

VRS01

-24¢JB

DOLBY NR REC qEC EO AMP BIAS REC

SYSTEM IC SENSE 5 C,_10 4 -RAP HEAD

)rPr208)

+ 2dB (METAL)

-0 5dB (CHROME)

-_ f'dB (NORMAL)

-15d£ (NORMS, L] !SdB (ME TAL)

O_B:Z7§mV

-20 5dB (CHROME) 21dB (NORMAL)

]

i DISASSEMBLY INSTRUCTIONS I

1. How to Remove the Front Panel

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

top cover. M_ve 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 _t

can be scratched easily.

(3, Remove the three screws (3 × 10 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

Screw

Top cover

Disconnect all lead connectors.

(3)

C Mechanism W151 (7P) -- CN151

Head wire _ CN301 | Audio Head wire _ CN302_ circuit

Meter circuit W131 (3P) _ CN131 / board board 23PFFC -_CB121 I

(4)

Remove Volume Knob and Volume Knob (C).

(5)

Remove the four retaining screws (2.6 × 6 CBTS(S)-Z) (3

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

(6)

Remove the Hooks at the left and right of the front face of the Front Esc. Ass'y, and the two hooks on the bottom, Front Ass'y can be removed towards the front.

MechenJsrn i-etain;ng Screw

Mechanism _'_

\ IBxO)

1 _f Mechc]nism retaining Screw

,." ! _(3x10

Knob C"

escutcheon

A_s'y

Cassette bax

panet

2 hooks on the top of the front panet

[

3 hooks on the bottom of the front panel

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 3 × 10 CBTS-(P)-B

holding the Front Escutcheon at the front.

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

3. How to Remove the Mechanisms

Remove the four Mechanism retaining screws 3 × 10 CB'[S(P)-B and take out C Mechanism

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(3 x 8CBTS.Ptight) 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 ma<e sure

that d:_s not floating ab3ve the circuit board If it is floating, the switch will oe in the on condition when

the set is assembled

C)N-730R I

HO0_

Meier Circuit Board

5. How to Remove the Cassette Door

(1) Remove :the MfNI]Zf_l_PER"_etaining screw _'-x 8 CBTS{P)-

B and take out tl_ MINI DAMPER

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

pull up to remove the CASSETTE BOX and BOX SPRING

sc_ew_ ,i __

Power supply

circuit b0crd

\,\

Ccrew

I',3X 8] )

Note: Almost all of the servire repairs to the audio cir-

cupt 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 procedu-es in the reverse order. However, if each of the various

parts are not asserrbled properly in their re_pec- twe position, the sel cannot be assembled in some cases. Theretore, check the work of each step carefully when assembling

7F TBG

Screw

.(3x10)

circuit board

¢smper --Box spring

Front surfaceofFroqtAss'y

6. How to Remove the Audio 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) Remove the connectors from the audio circuit boa{d and

power supply circuit board.

Side of the Side of the Power suppl,i CN901 -- (7P) _ CN901 audio circuit

circuit board TBG board

CONNECTOR

(4) Remove the screw (3 x 10 CBTS-P tight) (3 x 8 CBTS.S

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.

7. How to Remove the Power Supply Circuit Board

{1 _ Remove the to_ cover and the front oanel. (Refer to section

(2) Remove the bushing that is fixing the power suppl_ cord

from the chassis.

(3) When the five screws (4 x 1:3 CBTS.P tight;, (3 x 10

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.

Powe" supp(y circuit board

DN--730R

ADJUSTING AND CHECKING THE

MECHANISM SECTION

1. ReplacincTthe Pinch Roller (36)

Before replacincl" tl_e pinch roller, clean the tape contact surface o[ 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 mo_d.e_hpok a. spring weight opto the bracket at the center o; the pinch roller. After separating the pinch roller from the capsta'q s_'aft, allow fl_e pinch roller to contact the caps- t_n shaft again. Check to make sure the spring weight reads be- twveen 250-- 350 g when the pinch roller starts to rotate Replace the pinch roller (36) when it does not conform to the

slandard specification values.

Capstan shaft

4. Replacing the ERASE HI'AD (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

____F--ZZ_-:±-J

5. Checking the Take-up Torque

Load the cassette type torque meter ',SONY TW21:11 ). Check to make sure that the aver3ge torque meter reading is

within 30-70 g-cm during playback. If it is not within thi,_; range. check the voltage (approx. 4V) of th_ reel motor. If the voltage is low, the torque will be weak: if it is high, the torque will be strong

6. Checking the FFand RE\_/ Torques

Load the cassette type torque meier (SONY TW2231). Check to make sure the torque meter indicates within 90--180 g-cm at

the end of FF and REW.

Pinch roller

: i

_._ 250 -- 350 g

Replacing the Record/Playback Head (14)

(1)

How to remove _e RiP 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 mech_,nical unit to remove the record:playback head.

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

Reverse the above 1 procedures for removrng the R,"P HEAD

" Solder the HEAD WIRE according to the diagram

mechanism (re('ordingiplayback head)

7. Checking the Back Tension Torque During Record/Playback

Load the cassette type torque meter (SONY TW2i11): check to make sure the torque meter read_ 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.

8. Checking the FF and REW Times

Load a C-60 cassette tape (DENOI'4 GR-2/60); check to make sure the tape is fast forwarded o: rewound within 110 sec- onds. if it is not within this range, rheck 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 properl !, detecting the tape type de- tection holes on the cassette housin(.;

BROWN

BLUE

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