Toshiba XR Z90 Service Manual

Page 1

SERVICE TEXT
FILE NO. 1 77 - 1 7a

TOSHIBA

CDNFACT DISC PLAYER

XR-ZQD

SUBJECT: COMPACT DISC PLAYER TROUBLE SHOOTING MANUAL

REMARKS

PRINTED IN JAPAN 22905164 Feb., 1983 ©

Page 2

INTRODUCTION

Toshiba has developed a long-waited compact disc, "XR-ZQO", which allows us to make an entirely new
experience by providing a new audio source.

XR-ZQO has been designed attaching the greatest importance on sound quality and operatability to obtain
the best capability the compact disc has.

The sound quality of a compact disc player is greatly dependent on the property of analogue circuits in-
cluding aD/A converter. For this reason, a high-speed integrating type of a D/A converter is adopted.
Signal disturbance associated with scratches on the disc in compensated by making use of a one-beam
time-difference detection tracking servo. The keystone of operationablity of the CD player is a random
access to find out a start point of a desired piece of music or information. In addition, facilities to fulfil
this function, which include a program memory, a next-play and repeat-play, are fully provided, and the
operating system gets rid of an image of a desk-top small computer to create fashion of a delux audio pro-
duct.

Toshiba developed and marketed a CD player in November, 1982. Toshibas long-experienced technology
on the player won a high reputation as achieved on stereo products of an analogue system. Toshiba will
solicit your continued patronage on CD players as well. _

The instructions described in the following will serve as reference in servicing and understanding character-
istics and functions of the CD player. We also hope the reference may be helpful for further development
of Toshiba's technology in an AV system through your servicing activity.

Digital Audio Systems Engineering Development Dept.
Manager
A kira K urihara

CO NTE NTS
[_T_| GENERAL DESCRIPTION 0N XR-z9o ............................................... 2 to 22
BRIEF DESCRIPTION ON COMPACT DISC ............................... , ............. 2
1. DISC .................................................................... 2
2. CD System ............................................................ 2 and 3
FEATURES ................................................................. 4
PECIFICATIONS ............................................................ . 4
OPERATION ............................................................. 5 to 16
1-4-1 CONTROLS AND THEIR FUNCTIONS ....................................... 5 to 7
1-4-2 PREPARATION FOR PLAYBACK ......................................... 8 to 14
1-4-3 WHEN THE ERROR IS INDICATED ......................................... 15
1-44 CONNECTIONS ......................................................... 16
1-5 HANDLING OF THE COMPACT DISC .............................................. 17
.NONSENSE CALL (If it seems likes faulty, Check again.) ............................... 18 to 22
.TROUBLE SHOOTING ................................... . ...................... 23 to 26
-GENERAL ................................................................. 23
[1] DATA SAMPLING, TRACKING SERVO (1) AND CIRCUIT ........................... 27 and 28
[2] FOCUS SERVO, TRACKING COIL DRIVE AND CIRCUIT ............................ 29 to 31
[3] TRACKING SERVO (2) DROPOUI CONTROL AND CIRCUIT .......................... 32 to 34
[4] KICK CIRCUIT, EJECT CIRCUIT .............................................. 35 to 39
[5 ] SYSTEM CONTROL CIRCUIT ................................................ 40 to 44
[6] SYSTEM CONTROL (CPU 2), DISPLAY CIRCUIT .................................. 45 to 47
[7] PROCESS CIRCUIT ...................................................... 48 and 49
[8] SYSTEM CLOCK CIRCUIT, PROCESS CIRCUIT (2) ................................. so to 52

[9] PLL, BUZZER, FEED MOTOR CIRCUIT ......................................... 53 to 55

Page 36

[3] TRACKING SERVO (2) DROPOUT CONTROL CIRCUIT

[3-1]

( Tracking servo no good I

N

[4-1] Kick circuit (See Page 35)

ls KGC (0224 ® ) in H?
Y

(Servo is actuated during KGC = H)

N .
Is waveform as illustrated obtained at 0225 (D .7 fl 0225 0r 0224 no good

Y (See Page 34)
[2-3]
[32] (See Page 30)
. The word "Sound Skip" means that recorded sound is inter-
SOUYld SKIP rupted or a same passage is playbacked repeatedly due to
scratches, dusts, etc. attached on the disc.
N

-9 [4-1] Kick circuit

Is DINH 0308 in L?
(See Pages 35, 36 and 37)

Y

. N [I] 0314 1
Does 0308 go H as RF Is dropped out? (See Page 2;?

Y \_> (Refer to waveform shown in schematic diagram)
(See Page 34)

0234 When DTAC output is

Is DTAC edge detected? 0235 ®
"_-_\ (See Page 65)

Y \-) (Refer to waveform shown in schematic diagram.)
(See Page 34)
N

--> 0235, 0236, 0237

Is 0239 Base changed to L, when RF is dropped out?

Y

ls focus tracking coil drive voltage reduced for dropout control signal ON period?
--- ,

N \-> Refer to waveform J/Y

shown in schematic
0225 diagram under [2].

0226 (See Page 31)

[10~2] CLV NG
(See Page 57)

-32..

13-3]

( FOK does not go H. I

Is 0224 ® in L with RF signal being applied?

->N See [2] 0204

(See Page 31)

Lnot developed, refer to [12-13].

Y
N
0224 Q) = "H? --> 0224
Y
Y
0316 ® = H"? eD306
N
Y
0316 = L? ->0316
N
. . N
Is clock being supplied to 0316 ® ? [5] 0402 (D
I (See Page 44)
\-> [W Y
Signal
Is 0316 @ almost in L? N% [83] (See Page 51)
-\
Y
OK This is an error check signal which confirms whether the

Note: It is recommendable to check that the servo gain adjustment pot has been set

0 data read include errors or not. If the error(s) is includ~

ed, the signal goes H".

properly when checking Focus Servo & Tracking Servo circuits.

_33_

Page 45

[5] SYSTEM CONTROL CIRCUIT (CPU 1)
Address buses Address buses H" when HFsigna/ is being fed.

L " with laser 0N

System Control Circuit

Clocks for microcomputer, from process _____ m

circuit.
Almost L " in PLA Y operation.

Usual/y L " in FLA Y operation

0 data serial output
73.5mS narrow width pulse in PLA Y operation.

7.35 kHz clock
Memory RAM

Microcomputer
Initialize Circuit

(1406 Iono®

H" if power is turned off.

0407
015-8

C407 R403
53/50 IaDK

R402 UK

EJECTsignal to c

To processor circuit (J18, 19)

6.7K R410 IK

Da ta buses

#407
I.2K

Memory back -up Circuit

405
+ 3300/10

R408
IK

0405 0406

Enphasis switching L in Search.aperation

6404 0.0!

R405 R406
47K {OK

STOPat L
DISC Motor STARTat L

95v

C403 5600?
ON

Vcc DISC TRE CON S40!

zao:
r can»
D

R4I5
IK

Digital Mute L " in Mute operation

5ND TR| OUT

Enphasis switching H in emphasis actuated.

404
NJM555

IE].

0402
TMP8243P

R4 IK

To display circuit (J21 )

To display circuit (J21)
To klc circuit

Feed motor circuit

Communication buses for CPU 2.

__44_

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