Technics SH-GE50 User manual

B Specifications
@ Equalizer Section
Frequency response(center position)
Viaximum output voltage
Rated output voltage
Rated total harmonic distortion
nput sensitivity
Signal -to -noise ratio
Maximum input voltage
Input impedence
Gain
Band level controls
5Hz~100kHZ, -3dB
6V(1kHz)
1V
0.007%(20Hz~20kHz)
0.005%(1kHz)
1V
110dB(IHF'A)
6V
33 kQ
0+1 dB
+12dB to -12dB
(7 continuous variable
elements per channel)
— Contents
Page
CAUTIONS FOR AC MAIN LEADG.............:cccccccessseseeseeesseeeesseaees 2
OPERATION CHECKS iiiscsvecucicdeticavainccmdccavbrstaurcpintamanncentepeedeas 3~4
TERMINAL GUIDE OF ICs TRANSISTORS AND DIODES ........ 5
SCHEMATIC DIAGRAM. ...........cccccceessseseeeesensseeeesseesenesesaaeeensaaes 5~7
PRINTED CIRCUIT BOARD ..........c00cssscercssssssnssancsacssanccarssacseaeare 8~10
ORDER NO. MD9707075C2
Service Manual
Stereo Graphic Equalizer
Equalizer
SH-GE50
= : ene Black Type
Area
Suffix for
A
eB W
(EG) Germany and Italy |
Center frequency 63Hz, 160Hz, 400Hz, 1kHz
2.5kKHz, 6.3kKHz, 16kKHz
@ General
Power supply AC 230 - 240 V, 50 Hz
Power consumption 11W
Dimensions (W x H x D) 430 x 80.4 x 192.5 mm
| (16°9/,." X 3/55" X 7'%/,5")
Weight 1.8kg (3.95ib.)
Notes :
1. Specifications are subject to change without notice.
Weight and dimensions are approximate.
2. Total harmonic distortion is measured by the digital
spectrum analyzer.
Page
WIRING CONNECTION DIAGRAM. ..........ccccececceeeneeeeeseeseesesenenenees 11
CABINETPARTS LOCATION Sickie te eee 12
REPLACEMENT PARISLISDE wisisstisuceseatcais nsiiavnnuavianene came 13
RESISTORS & CAPACITORS xecicsustenceetietiscatenimcinics 14
4. WARNING
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 attemptto 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 Electronics (S) Pte. Ltd.
All rights reserved. Unauthorized copying and
distribution is a violation of law.

SH-GE50 |
— Caution for AC Main Leads
(For “EB” area code model only.) |
For your safety, please read the following text carefully.
This appliance is supplied with a moulded three pin mains plug for
your safety and convenience.
A 5-ampere fuse is fitted in this plug. |
Should the fuse need to be replaced please ensure that the
replacement fuse has a rating of 5-ampere and that itis approved
by ASTA or BSI to BS1362.
Check for the ASTA mark @® or the BSI mark CY on the body of
the fuse.
If the plug contains a removable fuse cover you must ensure that
it is refitted when the fuse is replaced.
If you lose the fuse cover, the plug must not be used until a
replacement cover is obtained.
A replacement fuse covercan be purchased from your local dealer.
CAUTION !
IF THE FITTED MOULDED PLUG IS
UNSUITABLE FOR THE SOCKET OUTLET IN
YOUR HOME THEN THE FUSE SHOULD BE
REMOVED AND THE PLUG CUT OFF AND
DISPOSED OFF SAFELY.
THERE IS A DANGER OF SEVERE
ELECTRICAL SHOCK IF THE CUT OFF PLUG
IS INSERTED INTO ANY 13-AMPERE
SOCKET.
If a new plug ts to be fitted, please observe the wiring code as
shown below.
if in any doubt please consult a qualified electrician.
IMPORTANT
The wires in this mains lead are coloured in accordance with the
following code:
Blue: Neutral
Brown: Live
As these colours may not correspond with the coloured markings
identifying the terminals in your plug, proceed as follows:
The wire which is coloured Blue must be connected to the terminal
which is marked with the letter N or coloured Black or Blue.
The wire whichis coloured Brown mustbe connected to the terminal
which is marked with the letter L or coloured Brown or Red.
WARNING: DO NOT CONNECT EITHER WIRE TO
THE EARTH TERMINAL WHICH IS MARKED WITH
THE LETTER E, BY THE EARTH SYMBOL — OR
COLOURED GREEN OR GREEN/YELLOW.
THIS PLUG IS NOT WATERPROOF—KEEP DRY.
Before use
Remove the connector cover.
How to replace the fuse
The location of the fuse differ according to the type of AC mains plug
(figures A and B). Confirm the AC mains plug fitted and follow the
instructions below,
Illustrations may differ from actual AC mains plug.
1. Open the fuse cover with a screwdriver.
Figure A
Figure B
2. Replace the fuse and close or attach the fuse
cover.
Figure A
Figure B

SH-GE50
Mi Operation Checks
"ATTENTION SERVICER" Some chassis components may have sharpe edges. Be careful when
disassembling and serving.
1. This section describes procedures for checking the operation of the major printed circuit boards .
2. For reassembly after operation checks or replacement, reverse the respective procedures.
Special reassembly procedures are described only when required.
3. Select items from the following index when checks or replacement are required.
¢ Contents
¢ Checking Procedure for Major P.C.B.
Mi Checking Procedure for Major P.C.B.
1. Checking of the Equalizer P.C.B.
QOx3
Equalizer P.C.B.
(Solder Side)
& }D [sne2129-1)
(Black)
\b )
[XTBS3+8JFZ1]
(Black)
2. To remove the front panel from bottom
chassis
Front Cabinet Catch
Catch
Remove the top cabinet.
Push the 3 catch and pull
the frontcabinet simultaneously
in the direction of arrow.
‘Step 2)
Q«2

SH-GE50
3. To remove Equalizer P.C.B.
Remove the top cabinet.
Step 2) Gap |
Remove the front cabinet. Oxi2 @ OO o 9 Oo
Step 4 |
Remove the Equalizer P.C.B.
in the direction of arrow @
Equalizer P.C.B. one c ]
[XTBS26+10J]
4. Checking of Input Selector P.C.B., Meter
P.C.B. and Power Switch P.C.B.
‘Step 1] Equalizer P.C.B. Input Selector P.C.B.
Follow procedure 3
Power Switch P.C.B:
Meter P.C.B.
(Solder Side)
5. Checking of Power Supply P.C.B. and
In/Output Terminal P.C.B.
Exp Cb In/Output Terminal P.C.B.
Remove the top cabinet.
Power Supply P.C.B.
(Imm +O
[XTB3+20JFZ]
(Black)

Mi Terminal Guide of ICs, Transistors and Diodes
M5229P
11
“Kg
i
25B621AQSTA
yA
PCs
SLR325MCT31
SLR325YCT31
Cathode”
Cao—tk}—0A
Anode
ai *
M5218AP
SLR342VC
Anode
Cathode” || }{7”
Cao—{kp}—0A
mM Schematic Diagram
(All schematic diagrams may be modified at any time with the development of new technology)
Note :
¢ S1
Power switch
MLC4066BH BAG144
MA2110BLF
Ca
‘il
Cathode
SLA370LT
SLA370MT
Cathode i
Cac—tk}—oA
: SH-GE50
RVTDTC143XST
25A933SSTA
23C1740SSTA
25D2374PQAU
B
Ce
MTZJ13BTA RL1N4003NO02
Ca
Ca
Cathode a Cathode
A a
A
Ea
Anode
° $201
¢ VR201 & VR202
¢ VR203 & VR204
¢ VR205 & VR206
Input Selector switch
Equaliser control ( 63Hz )
Equaliser control (1 60Hz )
Equaliser control ( 400HZ )
¢ VR207 & VR208
e VR209 & VR2010
¢ VR2011 & VR2012
e VR2013 & VR2014
Equaliser control ( 1kHz )
Equaliser control ( 2.5kKHz )
Equaliser control ( 6.3kHz )
Equaliser control ( 16kHz )
¢ Signal line
“ij + Playback signal line
AnC>
' +Bline
: Record signal line
: -Bline
: Main signal line
The voltage value and waveforms are the reference voltage of this unit measured by DC electronic voltmeter (high impedance) and oscilloscope on
the basis of chassis. |
Accordingly, there may arise some error in voltage values and waveforms depending upon the internal impedance of the tester or the measuring
unit,
elmportance safety notice:
Components identified by A\ mark have special characteristics important for safety. Furthermore, special parts which have purposes of fire-
retardant (resistors), high-quality sound (capacitors), low-noise (resistors), etc. are used. When replacing any of components, be sure to use only
manufacturer's specified parts shown in the parts list.
Caution!
iC, LSI and VLSI are sensitive to static electricity.
Secondary trouble can be prevented by taking care during repair.
«Cover the parts boxes made of plastics with aluminium foil.
«Ground the soldering iron.
«Do not touch the pins of IC, LSI or VLSI with fingers directly.
«Put a conductive mat on the work table.

SH-GE50
mi Schematic Diagram
Meiners
[eer 4
Pt |
—-
INPUT SWITCH
CIRCUIT
elit 24
. ©
al MIL
HO Hey
e L CH e
REC (OUT
es
TAPE
(MONITOR)
rt CHICO
iy rial
R CHO (9)
MUTING n
(>)
e118
Mw
NS <OV> o
£1 =
ae af
MLC4066BH | |
SWITCHING(ON/OFF) mg
IC2
M5218AP
BUFFER AMP
0217-D222 0231-0234 LT (L-T\ LT)
SLR325MCT31 SLA370LT y, SD q
0223-0226 0235,0236
SLR325YCTS1 SLR342VC
{C203 ,IC204
BA6144
LEO INDICATOR
(2) S rome)
<10.8V> <10.9V> <10.9V>
<OV> <OV>
A\R231 56
METER CIRCUIT
rt) (a
q

SH-GE50
CEE FILTER AMP/BAND LEVEL CONTROLS CIRCUIT
C223, | KO.033
IDI)
rays
P= OOP
C225
K680P
C226
K680P
C230
ov> KSSOP
a | 227
NH = K0.012
oF
2.EV>
>
<—2.1V>
~2.1V>
2.1V>
cree.
<OV> <OV> <OV
<
OV>
<OV> <OV>
()
<12,.5V>
van ah
oe oe,
(1 Sem] 7m Cm] S|) 3) 2) 7)
ae)
Se
sas
| |_|
ty I
wy (TS) sta
ag ey yp Na)
eae | Lee | epee | eee: | eerie! | Meera | Pree ee
[Eger | Spree! | renee | Neeser) | LESeere | mse! | Eo
R202
2.2K
\
war ragi,
16201 IC202
9229P
B.P. FILTER AMP
POWER/EQUALIZATION
SWITCH CIRCUIT
mE diim _f
ft
She
ans : ae 3
SS 0201 ge
Sek on 2SB621AQSTA
iS = iN POWER SUPPLY
ix
Q203
i 4 RVTDTC| 43XST
dws eee a 5 ae
Saas Seca
a ar a Pee ie)
meen aan pee aa
JW3A
sides
(aera
ET
A
>Peel of = 1601
“| 8] F 8 eEEE be sine REOS Ee
<12.5V>-~<20.6V>
c Ee ge ee ‘herr
|; of <13.1V)
iy wo
©
| | : A\YK601
()
| | x Z50V-240
Zz
[| 4
D601
MTZJ13BTA
Dé02
MA24 10BLF
D603-D606
RLIN4G03N02
SShos74pqay 0603S MAT ABTA
MUTING CONTROL oO
(POWER ON) ex
$C
1740SSTA
7
ee
tow
Say
auins
ORE
EJ POWER CIRCUIT

SH-GE50
M@ Printed Circuit Board
Cc
B.P
FILTER
AMP/BMP
BAND
LEVEL
CONTROLS
P.C.B.
(REP2485C-M)
(16KHz) (6.3KHz) (2.5KHz) (1KHz) (400Hz) (160Hz) (63Hz)
RIGHT = CHANNEL
IE) IN/OUTPUT TERMINAL/BUFFER AMP P.C.B. (REP2485C-M)
PLAY (IN
REC (OUT
OUT

SH-GE50
(16KHz) (6.3KHz) (2.5KHz) (1KHz) (400Hz) (160Hz) (63Hz)
LEFT CHANNEL
[=] POWER P.C.B. (REP2485C-M)
CAUTION
RISK OF ELECTRIC SHOCK
AC voltage line. Please do not
touch this portion.
AC IN~
Z250V—240V
SO0Hz

SH-GE50
[] POWER/EQUALIZATION [3 INPUT SWITCH P.C.B.
SWITCH P.C.B. (REP2485C-M)
(REP2485C-M)
= 4022