Technics ST HD 50 Service Manual

Page 1

ORDER NO. ADQ702015C2

ervice Manual

Tuner

System: SC-HDSO

* SB-HDSOA

ST-HDSO or
SbHDGO ST-HDSO

RS-HD70 SE-HDGO

Remote Control
Transmitter

Tuner
Colour
(N) ....................................... Gold
Area
(E) .................................. Europe.
it
System Areas Tuner

SC-HD50 (Germany. Italy.) : ST-HDSO
SC-HDsO (Europe. Russia.) : ST-HDSO

Because of unique interconnecting cables, when a compact requires service, 1

[ send or bring in the entire system.

Specifications
Pro-amplifier Section

Input sensitivity/Impedance
EXTERNAL: 250 mV/15 kohm
Output level
EXTERNAL: 250 mV/1.5 kohm
Frequency response
EXTERNAL: 50 Hz - 25 kHz
SIN
EXTERNAL: DIN 82 dB (83 dB, IHF)

FM tuner Section
Frequency range: 87.50 - 108.00 MHz (0.05 MHz steps)
Sensitivity: 1.8 uv (lHF usable)
SIN 26 an: 1.5 pV
S/N
MONO: 70dB (75 dB, iHF)
Stereo separation
1 kHz: 35 dB
Antenna terminal(s): 75 ohm (unbalanced)

System/SC-HDSO:

AM tuner Section
Frequency range: 522 - 1611 kHz (9 kHz steps)
530 - 1620 kHz (10 kHz steps)
Sensitivity (SIN 20 dB): 500 [JV/m
MAN: 80 dB

Timer Section
Clock: Quartz-lock type
Function: 24-hour programmable;
Play timer (1 time). Fiec timer (1 time)
Sleep (120 min.. 30 min., intervals)
Setting: 1 minute - 23 hours 59 minutes (1 min. intervals)

General
Dimensions: 196(W)/67(H)/235(D) mm
Weight: 1.2 kg

Notes:
Specifications are subject to change without notice.
Weight and dimensions are approximate.

Tuner: ST-HD5D or ST-HDGO, Compact Disc Player: SL-HDGO, Amplifier: SE-HDsO, Cassette Deck: RS-HD70, Speakers: SB-HDSOA

Notes: * ...... Made in PAES

AWARNING
This service information is designed for experienced repair technicians only and is not designed for use by the general public. It does not
contain warnings or cautions to advise non-technical individuals of potential dangers in attempting to service a product.
Products powered by electricity should be serviced or repaired only by experienced professional technicians. Any attempt to service or
repair the product or products dealt with in this service information by anyone else could result in serious injury or death.

Technics®

© 1997 Matsushita Electric Industrial 00.. Ltd.
All rights reserved. Unauthorized copying
and distribution is a violation of law.

Page 2

ST-HD50

l Contents

Location of Controls .
Setting the Time .....
About the Self~Diagnostic Mode ........................................................... 3
Operation Checks and

Main Component Replacement Procedures.
Type Illustration of ICs, Transistors and Diodes
To Supply Power Source
Schematic Diagram ......

4,5

NOTE:

Printed Circuit Board Diagram
Wiring Connection Diagram
Terminal Function of I05
Block Diagram ..............
Replacement Parts List (Electrical)
Resistors and Capacitors ..............
Replacement Parts List (Cabinet, Packing)
Cabinet Parts Location .............................

Refer to the service manual for Model No. SE-HD50 (ORDER No. AD970202203) for Information on Accessories",

Installation, Connections and Packaging".

l Location of Controls
1

4 6

l Setting the Time

The Inner display the time, frequency and other information
on CDs and tapes.

This is a 24-hour display clock.

These instructions explain how to set the timer for 16:25 on
Wednesday.

.Switch on the power.
E® Press CLOCK/TIMER 10 show CLOCK".

Every time you press the button, the indication changes in
the order of CLOCK -> G) REC -> 6 PLAY -- Original display.
Within 8 seconds:

(2) Press SET.

.(D Press V or A to select the day.
Every time you press one of the button, the indication changes in the
order of SUN 2 MON 2 TUE Z WED Z THU 2 FR] 2 SAT.

® Press SET.

HG) Press v or A to select the hour.
(2) Press SET.

ECD Press V or A to select the minutes.
® Press SET to finish setting the time.

The display will return to the previous display after about 3 seconds.

(D Remote control signal sensor (SENSOR)

® Record tlmer button (ED REC)

® Play tlmer button (Q) PLAY)

@ Clock/timer buttons (CLOCK/TIMER)

(53 Set button (SET)

© Tuning/time adjust button (V , A TUNING/TIME ADJUST)
® Tuning mode select button (TUNING MODE)

Source input select button (INPUT SELECTOR)

@ RDS display mode select button (RDS DISPLAY MODE)
® Band select button (FM/AM)

, . at
. it
,t '4 , .,
i .« i 1
1 .u
an , L,r < t z 1 4.31:.
t ».

0 0|: QID m l

:sf_>>e" a angst. e"

When - - : - - appears:

If flashes when you connect the AC power supply cord for the first time
or if there has been a power failure.

Reset the time as explained above.

If the minutes setting is off:

1. Press CLOCK/TIMER.

2. Press SET 3 times.

3. Press V or /\ to set the minutes, and then press SET.

To display the clock again:
Press CLOCK/TIMER.
The clock display will appear for about 8 seconds.

For your reference:
When you turn OFF the system from the POWER button, the system goes on
standby and the STANDBY indicator lights up.

_2_

Page 19

l Terminal Function of IC's
o ICQO1 (M38197MA146F) : SYSTEM CONTROL/FL DRIVE

ST-HD50

-19-

:2: Tflgnnirgal I/O Function 5': mm l/O Function
1 KEY-TU I Tuner operation switch signal input 33 ACK BK | Serial data input for RS-HD70
2 KEY»CH | Input selector operation switch signal input 34 AC IN I AC power in detection signal input
3 KEY-SE I SE-HD50 operation switch signal input 35 RESET I Reset signal input
4 KEY-CD l SL-HD60 Operation switch signal input 36 SD l SD control signal input for tuner circuit
5 NC -- Not used, open 37 STEREO | STEREO signal input for tuner circuit
6 DATA 1 0 Serial data output terminal 38 XIN I

Connected to the ceramic oscillator

7 CLK 1 0 Serial clock signal output terminal 39 XOUT O
8 DATA 2 0 Serial data output terminal 40 Vss - GND terminal
9 CLK 2 0 Serial clock signal output terminal 41 MUTE 0 Muting control signal output

10,11 NC - Not used, open 42 POWER 0 Power ON/OFF control signal output
12 SEL-TU 0 Tuner select signal output 43 CSI 2 I

Connect to GND through the resistor
13 STE 0 Strobe signal output 44 CSI 1 I
14 NC - Not used, open 45,46 050 3, 6302 0 Not used, open
15 CE 0 Chip enable output 47 CSO 1 0 Connect to GND through the diode
16 DATA IN I Serial data input terminal 48~60 G13 ~ G1 0 Grid control signal output
17 CEO 0 Serial data output terminal for (E,EG) areas 61 ~90 P36 ~ P7 0 Segment control signal output
18 DATA I/O l/O Not used, connected to GND 91 V00 - Power supply (+5V)
19 CE 335% | Serial data input terminal 92~97 P6 ~ P1 0 Segment control signal output
20 (fiplisrclifirf I Serial clock signal input terminal 98 -VP - Negative power supply
21 agggEgg$ 0 Serial data output terminal 99 AVSS - Connected to GND
22 cagggffif l Serial data input terminal 100 VREF - Reference voltage input terminal
23 MD CS | Chip select signal input for MD
24 MD REG 0 Request signal output for MD
25 DECK REG 0 Request signal output for RS-HD70
26 CD REG 0 Request signal output for SL-HDGO
27 CHECK 0 Clock checking terminal
28 CR TIMER I/O Capacitor and resistor oscillation terminal
29 CEI I Serial data input terminal for (E6) area only
30 REMOCON I Remote control signal input
31 V-JOGB l
Volume control signal input

32 V-JOGA l