Technics SUV 55 A Service Manual

Page 2

I CONTENTS

Page
LOCATION OF CONTROLS .......... PRINTED CIRCUIT BOARDS AND
PROTECTION CIRCUITRV .......... . - WIRING CONNECTION DIAGRAM . . . . 7 ~ 1!)
BEFORE REPAIR AND ADJUSTMENT ----------- 3 SCHEMATIC DIAGRAM ................... 11 ~ 15
DISASSEMBLY INSTRUCTIONS ............... 4. 5 BLOCK DIAGRAM ...................... 16, 17
MEASUREMENTS AND ADJUSTMENTS .......... G REPLACEMENT PARTS LIST ................ 18 ~ 20
EXPLODED VIEW ....... . . . . . . . . . . . .21, 22

I LOCATION OF CONTROLS

Balance control

bl
Tone contr<:Ils--[::;re )2)
ass

Power switch

volt
( age control) l-Amplifiar operation indicator

- (current drive

Loudness switch ( 1 off, -- on)

CD direct ll off, - on)
__Phono selector l 1 MM. - MC)

Volume control

Tone control

(1 direct, .- on)-E (H)

Headphones jack-m-e Di: DD

I- Input selector

(main)-
Speaker selector
( 1 off, - cam-Eiremote)

Recording-mode selector ---
(tape 1 >2, tape 2>1, aux, CD, tuner, phono)

indicators
(phone)
(tuner)
10
laux -lnput selectors
Tape 2/Ext
Tape l/DA tape

Tape 1/DA tape (Playback)
(Rec out)-
Tpae 2 (Playback)
[Ext (Rec out) AC inlet
Switched (50W MAX.j
U . had ACoutlets
"mm: (For XA areas]
(Total 200W MAX.)
Phono

[--'I
II Illll ODLLILl
ii Iiil i696; inl
l l l l 6 ® I I] U .
lo$$$$xe lll i "J

o o 0 Q3 Q Q

l-l
Ground- (Fl) (L) (R) (L) Voltage selector (on the bottom board)
(127V0110VH ZZOVHZ4OVI
Tuner (For [XA] area only)
CD
Aux

[-

Remote speaker terminal

Main speaker terminal

_2_

o The power supply for this unit varies depending upon the areas. Also, the parts used for power supply are different.
80, refer to the circuit diagram and replacement parts list.
* [XA] area is provided with voltage selector and AC outlets.

at

at

a

240V (50/60Hz) for Australia and United Kingdom.
220V l50/60Hz) for Continental Europe.
127V/110V/220V/24OV (50/60Hz) for other [XA] area.

" Phono input capacitance is about 1009':-

Suggestions

Olf noise is very annoying while listening to an FM or AM
broadcast, switch OFF the video disc player, compact-disc
player and turntable.

oSwitch OFF the video disc player power if noise is
excessive while listening to an audio tape, compact disc or
regular phone disc.

Notes:

oTo record sounds from a compact disc. press the input
selector marked "CD".
The compact-disc-direct switch is for listening only; it
cannot be used to select the compact disc as a recording
source.

I PROTECTION CIRCUITRY

The protection circuitry may have operated if either of the following conditions is noticed:
' No sound is heard when the power is switched ON.
0 Sound stops during a performance.
The function of this circuitry is to prevent circuitry damage if, for example, the positive and negative speaker connection wires
are "shorted" , or if speaker systems with an impedance less than the indicated rated impedance of this unit are used.
If this occurs, follow the procedure outlined below:

i .

2.

3.
Note:

Switch OFF the power.
Determine the cause of the problem and correct its
Switch ON the power once again.

When the protection circuitry functions, the unit will not operate unless the power is first switched OFF and then ON again.

I BEFORE REPAIR AND ADJUSTMENT

[1) Turn off the power supply. Using a 1052, SW resistor, shortcircu it both ends of power supply capacitors (C705, C706,
8200 uF) in order to discharge the voltage.

(2) Before turning on the power switch of the set .

A.
B.

C

011

Connect the voltage controller to the primary side.
Connect the AC ampere meter to the primary side or connect the DC voltage metar to the "i B" circuit of the
secondary side.

, Turn the VR of ICC) (VR401 and VR402) to minimum (counterclockwise).
. After setting the output to zero of the voltage contoller, turn on the power switch of the set.

And increase the output of voltage controller gradually.
Then, check carefully whether the current value of primary side become more than followings value or whether
the DC voltage of secondary side is increasing slowly.

. If the value of current is increasing unusually or the DC voltage is not increasing, lower the output level ofvoltage

contoller immediately.

. Check the transistors of voltage amplifier and current amplifier lCSOl.
. After repairing, adjust the ICQ.

The current value of the primary side at no signal. (Confirm the power supply voltage of each area and provided
voltage of the set.)

Power supply voltage AC110V AC1 27V ACZZOV A6240V

Consumed current 50/60H2 280 ~ 560mA 260 ~520mA 140 ~ 280mA l30~ 260mA