Technics SAEX 110 Service Manual

Page 2

SA-EX1 10

A 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 cautionsto 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 attempt to service or repairthe product or products dealt with in this service
information by anyone else could result in serious injury or death.

I Contents page

SAFETY PRECAUTIONS ................. r. 2 WIRING CONNECTION DIAGRAM
BEFORE REPAIR AND ADJUSTMEN 2 BLOCK DIAGRAM
PROTECTION CIRCUITRY ................. .. 2 SCHEMATIC DIAGRAM
OPERATION CHECKS & MAIN COMPONENT REPLACEMENT 3 ~ 6 CABINET PARTS LOCATION
TROUBLESHOOTING ........... .. 7 ~ 8 REPLACEMENT PARTS LIST
TERMINAL FUNCTION OF ICs . 9 RESISTORS & CAPACITORS
TERMINAL GUIDE OF ICs TRANSISTORS AND DIODES . 9 PACKAGING"

PRINTED CIRCUIT BOARD ,. 0 ~ 13

I safety Precautions (This "Safety Precaution"' Is applied only In U. S. A.)

waver

Before servicing unplug the power cord to prevent an electric shock.

When replacing parts, use only manufacturer's recommended components for safety. Antenna

Check the condition of the power cord. Replace if wear or damage is evident . mini.

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

Before returning the serviced equipment to the customer, be sure to make the following insulation Exposed

resistance test to prevent the customer from being exposed to a shock hazard . mm. /
part

Ohmmeter
Fig. I

Resistance = 3M9 - 5.2Mfl

- Insulation Resistance Test

1.
2.
3

Unplug the power cord and short the two prongs of the plug with ajumper wire.

Turn on the power switch .

Measure the resistance value with ohmmeter between the jumperAC plug and each exposed metal
cabinet part ,such as screwheads, antenna ,control shafts ,handle brackets, etc . Equipment with antenna

terminals should read between 3M9 and 5.2M!) to all exposed parts ,(Fig. 1 ) Equipment without age:
antenna terminals should read approximately infinity to all exposed parts . (Fig, 2) Part
*Note :Some exposed parts may be isolated from the chassis by design. These will read intinity .

It 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 . Resistanoe= Approx w

lBefore Repair and Adjustment

Disconnect AC power, discharge four Power Supply Capacitors (C703 to 0706) through a 100 , 5W resistor to ground.
DO NOT SHORT-CIRCUIT DIRECTLY (with a screwdriver blade, for instance), as this may destroy solid state devices.
After repairs are completed, restore power gradually using a variac, to avoid overcurrent.

Current consumption at 120V, 50 Hz in N0 SIGNAL mode should be less than 1000mA.

I Protection Circuitry

The protection circuitry may have operated it either of the following conditions are noticed:

The function of this circuitry is to prevent circuitry damage if, for example, the positive and negative speaker connection wires are "shorted"

- No sound is heard when the power is turned on.
0 Sound stops during a performance.

or if speaker systems with an impedance less than the indicated rated impedance of the amplifier are used.
If this occurs, follow the procedure outlines below:

1. Turn off the power.
2. Determine the cause of the problem and correct it.
3. Turn on the power once again after one minute.

Note:
When the protection circuitry functions. the unit will not operate unless the power is first turned off and then on again.