Technics SA-EH780E User manual

AD0202025C2
Tuner/Amplifier
SA-EH780E / SA-EH780EB / SA-EH780EE / SA-EH780EG / SA
-EH780EP
Colour
(N)...................GoldType
SPECIFICATIONS
2002 Matsushita ElectricIndustrial Co., Ltd. All rights reserved.
Unauthorized copying and distribution isaviolation of law.
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1. Before Repairs
1. Turn off the power supply. Using a10 , 10 Wresistor, connect
both ends of power supplycapacitors (C701, C703 and C702,
C704) inorder to discharge the voltage.
2. Before turning the power supplyon, after completion of repair,
slowlyapplythe primaryvoltage byusing apower supplyvoltage
controller to make sure that the consumed current at 50 HzinNO
SIGNALmode shouldbe shownbelow with respectto supply
voltage 230/240 V.
Powersupply
voltage AC 230 V AC 240 V
Consumedcurrent
50 Hz 100 - 350 mA
2. Protection Circuitry
The protection circuitrymayhave operatedif eitherof the following conditions is noticed:
-Nosound isheard when the power isswitched ON.
-Sound stops during aperformance.
The functions of this circuitryis toprevent circuitrydamage if, forexample, the positive and
negative speakerconnection wires are shorted, orif speakersystems withanimpedance less
thanthe indicatedratedimpedance of this unit are used.
If this occurs, followthe procedures outlinedbelow.
1. Switch OFF the power.
2. Determine the cause of the problem and correct it.
3. Switch ONthe power once again.
Note:
Whenthe protection circuitryfunctions, the unit will not operate unless the poweris first
switchedOFF and thenON again.
3. Accessories
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-AC power supplycord for SA-EH780E, SA-EH780EE, / SA-
EH780EG, SA-EH780EP / (RJA0019-2X)................................1pc.
-AC power supplycord for SA-EH780EB/ (RJA0053-
3X)................................1pc.
-AMloop antenna set / (RSA0022-L)..................................1pc.
-FM indoor antenna / (RSA0007)......................................1pc.
-Speaker cords / (REE0853)....................................2pcs. /
(REE1057)....................................2pcs.
-Remote control transmitter / (EUR7702050)..............................1pc.
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-Remote control batteries / (R6/LR6, “AA”, UM-3)...................2pcs.
Note: These are availableon sales route.
-Antenna plug adaptor for SA-EH780EBonly/
(SJP9009)......................................1pc.
4. Caution for AC Mains Lead
4

5. Location of Controls
6. Operation Checks and Component Replacement /
Procedures
-Thissection describes procedures for checking the operation of
the major printed circuitboards and replacing the main
components.
-For reassemblyafter operation checks or replacement, reverse the
respective procedures. Special reassemblyprocedures are
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described onlywhen required.
6.1. Checking for the AC INP.C.B.
-Check the AC INP.C.B. as shownbelow.
6.2. Checking for the operation P.C.B.
-Follow the (Step 1) -(Step 3) of item 6.1.
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-Check the operation P.C.B. as shownbelow.
6.3. Checking for the mainP.C.B.
-Follow the (Step 1) -(Step 3) of item 6.1.
-Follow the (Step 1) -(Step 6) of item 6.2.
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8

-Check the mainP.C.B. as shownbelow.
6.4. Replacement for the regulator transistor
-Follow the (Step 1) -(Step 3) of item 6.1.
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6.5. Replacement for the power IC
-Follow the (Step 1) -(Step 3) of item 6.1.
-Follow the (Step 1) -(Step 6) of item 6.2.
-Follow the (Step 1) -(Step 11) of item 6.3.
7. To Supply Power Source
This unit is designedtooperate on powersuppliedfromsystemconnected. / Forsystem
connection, referto Fig. 7-1.
Fig. 7-1.
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