Technics SUC 1000 Service Manual

Page 2

SU-C1000

l Contents Page

Safety Precaution ...................................................... . ......................
Before Repair...
Protection Circuitry
Caution for AC Mains Lead
Accessories ..................................
Inserting the Rechargeable Battery
Connections ..
Power Supply
Forced Switching to Battery Power for Testing and Maintenance
Bttery Notes ............
Front Panel Controls
Using Battery Power...

I Safety Precaution

[for (P) area code model only]
1 , Before servicing. unplug the power cord to prevent an electric shock.

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Listening to Sound ..............................................................
Recording ...............................................................................
Operation Check and

Main Component Replacement Procedures
Schematic Diagram .
Printed Circuit Board Diagram
Wiring Connection Diagram
Block Diagram
Function of lC Terminals
Replacement Parts List
Cabinet Parts Location
Packaging ................

2. When replacing parts. use only manufacturers recommended components for safety.

3. Check the condition of the power cord. Replace ifwear or damage is evident.

4. After servicing. be sure to restore the lead dress. insulation barriers. insulation papers, shields. etc.

5. Before returning the serviced equipment to the customer. be sure to make the following insulation resistance test to prevent the customer from

being exposed to a shock hazard.
O INSULATION RESISTANCE TEST

1. Unplug the power cord and short the two prongs of the plug with a jumper wire

2. Turn on the power switch.

3, Measure the resistance value with ohmmeter between the jumpered AC plug and each exposed metal cabinet part. such as screwheads antenna.
control shafts. handle brackets. etc, Equipment with antenna terminals should read between 3 M9. and 5.2 M9 to all exposed parts. (Fig. A)
Equipment without antenna terminals should read approximately infinity to all exposed parts. (Fig. B)

Note: Some exposed parts may be isolated from the chassis by design. These will read infinity.

/

Antenna

terminal \4 I-
I
t
l
,(5

/

Exposed
metal part

Ohmmeter
(Fig.A)
Resistance : 3 M9 - 52 M9

/

Exposed /
metal part

Ohmmeter
(Fig- 5)

Resistance : Approx. 00

4. If the measurement is outside the specified limits. there is a possibility of a shock hazard. The equipment should be repaired and rechecked before

it is returned to the customer.

I Before Repair

(1) Turn off the power supply. Using a 10 £2. 10 W resistor. connect both ends of power supply capacitors (0611. 0651) 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 50/60 Hz in NO SIGNAL mode should be shown below with respect to supply voltage 120 Vl230 V/240 V.

Power supply voltage AC 120 V. 60 Hz

AC 230 V, 50 Hz AC 240 V, 50 HZ

30 ~ 55 mA

Consumed current

8~22mA 8-22mA

I Protection Circuitry

The protection circuitry may have operated if either of the following conditions is noticed:

0 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.

Ifthis occurs. follow the procedure outlined below:

1, Switch OFF the power.

2. Determine the cause of 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 tirst switched OFF and then 0N again.

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