Nakamichi OMS 5E Service Manual

Page 2

CONTENTS

NH

10.
11.

General ...................................................................... 2
Pickup Replacement Procedures .................................................... 2
2. 1. Notice in Handling Pickup ............................................... 2
2, 2. Pickup Replacement Procedures ........................................... 2
2. 3. Adjustment After Replacement of Pickup ....................................... 3
Measurement Instruments and Test Discs ............................................... 4
Parts Location for Adjustment ...................................................... 4
4. 1. Parts oanCB Assy ..................................................... 4

4 2. Parts on Pickup ............................ 4
Adjustments .................................... 5
5. 1. Notes ................................... . . . . 5
5. 2. Adjustment Instructions ................................ . . . . 5
Mechanism Assy and Parts List .............................................. . . . . . 1o
6. 1. Synthesis ............................................................ 1o
6, 2. Front Panel Assy (A01) 11
6. 3. Chassis Assy (A02) ..................................................... 12
6. 4. Disc Mechanism Assy (B01) .............................................. 13
6. 5. Rear Panel Assy (302) ................................................. 15
6. 6. Disc Mechanism Sub Ass y (001) ............................................. 15
6. 7. Analog Processor Unit (D01) .............................
Mounting Diagrams and Parts List ..................................
7 1. Photo Transistor P. C B. Ass y .............................. 17
7. 2. Photo Diode P. C. B. Ass y ................................ 17
7. 3. Open End Switch P.C.B. Assy 17
7. 4. Close End Switch P.C.B. Assy 17
7. 5. Eject/Load Switch P.C.B. Assy .............................................. 17
7. 6. Power Switch P.C.B. Assy ................................................. 17
7. 7. Remote Control P.C.B. Assy .............................. 17
7. 8, Pin Jack P.C.B. Ass'y ..................................................... 1s
7. 9. FL Indicator P.C.B. Assy .................................................. 18
7. 10. Auto Power Control P.C.B. Assy ............................................. 19
7. 11. RF PrevAmp. P.C.B. Assy ................................................. 20
7. 12. Power Supply P.C.B. Assy ................................................. 21
7. 13. Control Switch P.C.B. Assy ................... ' ............................. 22
7. 14. Analog Processor P.C.B. Assy . . .............................................. 22
7. 15. D/A Converter 1. C. B. Assy ................................................ 23
7. 16. Main P. C. B Assy ....................................................... 26
Schematic Diagram .............................................................. 27
8. 1. IC Block Diagrams and Descriptions ........................................... 27
8. 2. Waveforms at Major Points ................................................. 37
8. 3. Schematic Diagram ...................................................... 38
Wiring Diagram ................................................................ 39
Block Diagram ................................................................. 40
Specifications ................................................................. 41

Page 10

STEP ITS! SIGKAL OUTPUT ADJUST REMARKS
SOURCE CONNECTION HINT
11 Tracking Approx. Positive Main P.C.B. Perform this adjustment only if a disc with
Adjustment 0.1mm side of 0173 RV108,RV109 eccentricity is not played back properly.
with Eccentric on Main RM 10
Eccentric Disc P.C.B. Precisely re-adjust step 3 "Tracking Servo Disc
Disc Adjustment" and Step 6 "Tracking Screw Adjustment",

and check whether playback is made properly. If
not, perform the following adjustment to insure
correct tracking for a 0.1 mm eccentric disc.

1. Preparation for 0.1 m Eccentric Disc

Find a disc with approx. 0.1 m eccentricity in
the following manner:

a.

b.

Set a synchroscope to DC input and connect
it to the positive side of 0173 on the Main
P.C.B. Ass'y.

Play back the first music on eccentric discs
and press the Pause button to set the Cour
pact Disc Player in Pause mode. Then
observe the peak-to-peak level (Vpp) on the
synchroscope. The amount of eccentricity, X
(m), is given in the following formula:

x = 1/2 x (1.3 x (Vpp/(5.8 + [0.7))

where, 1.3 nm/A: sensitivity of Tracking
Servo
5.8 ohms: DC resistance value of
Traking Coil
4.7 Ohms: value of resistor R197

If amount of eccentricity (X) is assumed to
be 0.1 mm,

Vpp = 2 x (5.8 + lo.7)/l.3 x 0.1= 1.6 (V)

That is, the disc which shows approx. 1.6 V
on the synchroscope should be selected.

2. Load the disc found in 1 above and play back
the first music of the disc. check whether it
takes much time to enter Standby mode or
whether the time indication of the Time
Indicator begins with 00:00.

If not, re-adjust Step 3 "Tracking Servo
Adjustment" and then turn RV108 approx. 10
degrees in the counterclockwise direction.
During playback, press the F. Fwd button
several times and check that the time
indication of the Time Indicator regularly
increases.

If not, turn Rv109 to correct it.

Next, during playback, press the Rev button
several times to see whether the time
indication of the Time Indicator regularly
decreases.

If not, turn RVllO to correct it.

net i 1» gm.

4:

Page 11

6. MECHANISM ASS'Y AND PARTS LIST

6.1. Synthells
L07 I
I6
Fifi. 6.1
saggy me No. Descrivtlon Qw 5,35";ng Part No. Description W
synthesis 14 0080721A Bottom Cover 1
15 0080722A Lei 4
01 OCSIZOSA Indicator Lens 1 16 0M046218 Caution Label 3 1
02 CA80295A Front Panel Assy OMS-5 1 L01 0E00921A 31 3x8 $Bind1n§ 6
CA80296A Front Panel Assy OMS-5E 1 (Black Chromate)
CA80297A Fxont Panel Asly OMS-50 1 L02 0E00855A BT 2.61:6 enmdm 2
03 0080715A Elect Button 1 L03 0C81064A M4x8 9PM Washer-[Iced 4
04 0C80716A Lid 1 (Black 01120111318)
05 0080717A Lid Frame 1 L04 0E00970A M3x4 9 Binding 8
06 0080713A Eiect Button Base 1 L05 OEOOSSSA BT 3x12 9 Binding 4
07 CA80237A Eject/Load switch P.C.B. ASSY 1 L06 0081267A Shipplnz Washer 1
03 ~ Chassis Atsy 1 L07 OCB 1095A Shipping Screw 1
09 0080719A Top Cover 1
10 OM043'17A Caution Label A 2
1 1 0C8 0720A Vibration Isolating Sheet A 1
12 OCSIOGZA Vibntlon lsolatinz Sheet B 1
(except U.S.A.)
18 0C81063A Vlbtation Isolatini Sheet 6 1
(U.SAA.)

10

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Page 34

Description of Dilitnl Filter 10 U507 (SAA'1030)
(See Figs. 8.1.21 and 8.1.22.)

Pin Description of Digital Filter 10:

Signal In] Pin Signal In]

Name fl Desc 'on No. Name Out Description

VBB In --2.5 V 20.5 V mpply. 17 DRCF In Right channel data input. Data should be 16

OS In Offset select input. when connected to hit serial. MSB first. offset binary coded. It
VDDI the data output has a fixed DC should be valid on the falling edge of the
offset of 3%. When connected to VSS the data clock CLCF.
output has no offset. (This pin is connected 18 CLCF In Input data clock. The falling edge of this
to VDDl.) signal defines input data valid.

3 DLFD Out Left channel data output. The data is 14 bit 19 CLOX In Master input clock. Runs continuously at a
serial, MSB first and is valid on the falling nominal frequency of 4.2336 MHZ.
edge of output clock CLFD. 20 DLCF In Left channel data input. See DRCF.

6 CLFD Out Output data clock. nominal frequency 21 STRl In Input 44.1 kHz strobe. The circuits internal
4.2336 ME: (= CLOX). The falling edge of timing chain is synchronized by the rising
this signal defines output data valid. edge of STRI which must run synchro-

7 LAI Out Output 176.4 kHz strobe. The rising edge of nously with CLOX in accordance with the
th's pulse says that the output of a 14I bit timings specified in the electrical
data word has been completed. characteristics.

10 DRFD Out Right channel data output. See DLFD. The rising edge should follow the
11 (TE In Offset binary not input. When connected to completion of the input data stream.
VDD1 the output data is coded as 23 22 RT In Reset test not input. When low resets the
complement. when connected to vss the part of the accumulator not reset in nonnal
output data is coded as offset binary. (This operation to initialize the accumulator for
pin is connected to VSS.) testing. In normal operation should be
12 V53 -- Ground. _ connected to VDDI.
l3 VDD2 In 12V $1096 supply. 23 TE In Test enable not input. when low switches
15 TINR In Test input (R). Right channel test chain the internal circuitry into the sequential
input. In normal operation this pin should scan test mode. In normal operation should
be connected to either VSS or VDDl. be connected to VDDl.
16 TINL In Test input (L). Left channel test chain 24 VDDl In 5V 110% SUBDIV-
input. see TINR.
r- -_-"-I
TIN R at: :g' V33
TIN L |6 |2 V55
Fr 22 TEST --> m 24 vnur
._ ROM
TE 23 its vnoz
I Input I: Rec": . om ur I
DLCF 20 gm. smn Multiplier --> Am -> shif' -> 3 UL
WC" 7) Reqisler Reqisver Mulater Register 01 (DRFD)
CLCF leg: I
5 2' Iiming a Conlro! _
5 CLFD
CLOX x9;-> 37 LAT
L _. _ J
2 l |
os 36

Fig. 8.1.21 Digital Filter 10 SAA'IOSD

35

f
\

a iwee-«ewes-ee- ee or a. goose,

{9
Q
£3
@
d
E
®
Q
@

(Input)
ELOX
1:ch
m
rum-m
nLcr/aacr an
rum-2mm
sun
(usahzu
(Output)
m H Fl ['1 [-1
rum-r-
mam-Gr
WW lTITmTI'TTTTH m'ITmTHTITI WHTITTTTmTI JTFFTTI'I'I'IITFFI ['[TH'ITH'IT'ITU
mama/m
Fig. 8.1.22 Input/Output Waveform (SAA7030)
Dam IN I I

_ Shin Register
Clock 28

Lalch Enable 2

22 Analog cum
5 GND

25
24
v16 4 23
we 7 2|
Decouphnq
V26) || 20 Binary
Weighled
'9 Cunenl
Vref, 3 ,8 Sources
I4
05:. a ll
Capacitor 5 I2
Vie]. ro

Oscillator a
4- Bit
sum Register

5
Current

Reference |6
Source n

|
l
l
l
L
t
L
L
T
f.
t
t

Fig. 8.1.22 D/A Converter IC TDA1540D

36