Technics SU-VZ220 - Before Repair Procedures; Protection Circuitry

SU-VZ220
m CONTENTS
Page Page
BEFORE REPAIR ....... eee cee eect e nett eenes 2 WIRING CONNECTION DIAGRAM ........0 00.0 e cece eee 12
PROTECTION CIRCUITRY ...... 6. 6c eee eee 2 PRINTED CIRCUIT BOARDS ................0..0000- 13~16
ACCESSORY.
x.
oi
ceca
cuinetag
tah
yas
gaa
gemma
hurne
awa
2
BLOCK
DIAGRAM...
1...
ccc
cence
tenes
17
LOCATION OF CONTROLS ....... 02. ccc ce eee ere eee 3 REPLACEMENT PARTS LIST ...........0. 0200 secu 18~20
CONNECTIONS
22.0...
cece
teen
een
neee
4,56
CABINET
PARTS
LOCATION...
0...
eee
eee
es
21,22
DISASSEMBLY INSTRUCTIONS ......... 6... eee eee eee 6~8 PACKAGING 815. Fs.o 5 nn eo avers acai tpsed 54 ddd aehacec ais Soong walbey 23
SCHEMATIC DIAGRAM ........... cece eee eee eee 9~11
m@ BEFORE REPAIR
(1) Turn off the power supply. Using a 10, 5 W resistor connect both ends of power supply capacitors (C705, C706, 4700 LF) in
order to discharge the voltage.
(2) Before turning the power supply on, after completion of repair, slowly apply the primary voltage by using a power supply
voltage controller to make sure that the consumed current at 50 Hz/60 Hz in NO SIGNAL mode should be shown below with
respect to supply voltage 230 V/240 V.
AC 230 V AC 240 V
47~157mA 45~150 mA
@ 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.
“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:
1. Switch OFF the power.
2. Determine the cause of the problem and correct it.
3. Switch ON the power once again.
Note:
When the protection circuitry functions, the unit will not operate unless the power is first switched OFF and then ON again.
m ACCESSORY
@AC Power Supply cord 2.0.0.0... ccc cece eee ens 1
RJAQOIS-1K 0. ee eee For (EG) and (EP) areas
SIA193” svi sian qase Mathacngie wuantalerh abd as ges For (EB) area
SIANTS iicse derail idipiegese tone nwawr ses For (GN) area
Configuration of the AC power supply cord differs according to
area.