Technics SC-EH760 User manual

AD0004083C3
Tuner/Amplifier
SA-EH760
Colour
(S)....................SilverType
Areas
(GC)..................Asia, LatinAmerica, MiddleNearEast and Africa.
(GN)..................Oceania.
SPECIFICATIONS

1. BeforeRepairs
1. Turnoff thepowersupply. Using a10 , 10 Wresistor, connect
bothendsofpowersupplycapacitors(C701, C703 and C702,
C704) inordertodischargethevoltage.
2. Beforeturning thepowersupplyon, aftercompletion ofrepair,
slowlyapplytheprimaryvoltagebyusing apowersupplyvoltage
controllertomake surethat theconsumedcurrentat 50 HzinNO
SIGNALmodeshouldbeshownbelow.
For (GC) area
Powersupply
voltage AC110 V, 50 Hz AC240 V, 50 Hz
Consumed
current 200-700 mA 100-350 mA
For (GN) area
Powersupply
voltage AC240 V, 50 Hz
Consumed
current 100-350 mA
2. Protection Circuitry
Theprotection circuitrymay have operatedifeitherofthefollowing conditionsisnoticed:
-Nosound isheardwhenthepowerisswitchedON.
-Sound stopsduring aperformance.
Thefunctionsofthiscircuitryistopreventcircuitrydamageif, for example, thepositive and
negative speakerconnection wires areshorted, or ifspeakersystemswithanimpedance less
thantheindicatedratedimpedance ofthisunitareused.
Ifthisoccurs, followtheprocedures outlinedbelow.
1. SwitchOFF thepower.
2. Determinethecause oftheproblemand correct it.
3. SwitchONthepoweronce again.
Note:
2

Whentheprotection circuitryfunctions, theunitwill notoperate
unless thepowerisfirst switchedOFF and thenONagain.
3. Accessories
-ACpowersupplycordfor(GC)area / (RJA0019-X)...........................1
pc.
-ACpowersupplycordfor(GN)area / (RJA0035-X)...........................1
pc.
-AMloop antennaset / (RSA0022-J)...........................1pc.
-FMindoorantenna/ (RSA0006-J)............................1pc.
-Speakercords/ (REE0393)..............................2pcs. /
(REE0984)..............................2pcs. / (REE0985)..............................2
pcs.
3

-Remote control transmitter/ (RAK-EHA28WH)..................1pc.
-Remote control batteries / (R6/LR6, “AA”, UM-3)...........2pcs.
Note:These areavailableon sales route.
-Powerplug adaptorfor(GC)area only/ (SJP5213-
2)...........................1pc.
4. Location of Controls
5. Operation Checks and Component Replacement
Procedures
4

-Thissection describes procedures forchecking theoperation of
themajorprintedcircuitboardsand replacing themain
components.
-Forreassemblyafteroperation checks orreplacement, reverse the
respectiveprocedures. Special reassemblyprocedures are
describedonlywhenrequired.
/
5.1. Checking fortheACINP.C.B.
-Check theACINP.C.B. as shownbelow.
5.2. Checking fortheoperation P.C.B.
-Follow the(Step1) -(Step3) ofitem5.1.
5

-Check theoperation P.C.B. as shownbelow.
5.3. Checking forthemainP.C.B.
-Follow the(Step1) -(Step3) ofitem5.1.
-Follow the(Step1) -(Step7) ofitem5.2.
6

7

-Check themainP.C.B. as shownbelow.
8

5.4. Replacementfortheregulatortransistor
-Follow the(Step1) -(Step3) ofitem5.1.
5.5. ReplacementforthepowerIC
-Follow the(Step1) -(Step3) ofitem5.1.
-Follow the(Step1) -(Step7) ofitem5.2.
-Follow the(Step1) -(Step12) ofitem5.3.
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6. ToSupplyPowerSource
ThisunitSA-EH760 isdesignedtooperateon powersuppliedform system connected. / For
system connections, referto Fig. 6-1.
Fig. 6-1.
WhentheunitSA-EH760 has totestand service alone, use thefollowing method tosupplypower
source.
1. Shortthesection betweenW902APin3and C740 (-) (GND). Refer
to Fig. 6-2.
2. Connect thisunittoanACpowersupplycord. / (Thisunitcometo
stand-bymode.)
3. TurntheunitON.
Fig. 6-2.
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