Luxman pd 277 service manual

Page 2

CONTENTS

EXPLANATION OF OPERATION ............................. 1
ALIGMENT PROCEDURE ................................ 2 ~ 4
EXPLODED VIEW ........................................ 5
EXPLODED VIEW PARTS LIST ............................... 6
CONTROL P.C.B. PARTS LIST ..................................... 7
MOTOR P.C.B. PARTS LIST ....................................... 8
SPECIFlCATIONS ............................................... 9
PD-277 SCHEMATIC DIAGRAM ............................... 10 '11

EXPLANATION OF OPERATION

(1)

(2)

(3)

(4)

(5)

PLAY
When the PLAY button is pushed, both the SCRl and SCR2 are turned ON.

(a) The sub-motor starts rotating when the SCR2 is switched on, which makes the main gear rotate and the gear switch

on. Therefore even if the play switch is turned off, the sub-motor keeps rotating and operating until the gear switch
is turned off after one rotation.
By the rotation of sub-motor, the rotation plate is pressed to the delivering arm, and at the same time, the
delivering arm starts rotating, which, in case that the tone arm is out of the arm-rest, gets the tone arm returned to
the arm-rest side in the former half of rotation, then gets it conveyed to the lead-in position of the LP or EP record
in the latter half of rotation. The gear switch is turned off when the gear gets one rotation, and the rotation plate
gets away from the delivering arm, and the tone arm gets free for operation and keeps on playing.

(b) When the SCRl is turned on, the solenoid starts rotating according to the selection at speed selector, LP (33rpm) or
EP (45rpm).
At the LP position, the rotating angle of the selector gets the bigger one, and the rotation of the delivering arm stops
at the lead-in position of the LP, while at the EP position, the rotating angle of the selector gets the smaller one, and
the rotation of the delivering arm stops at the lead-in position of EP.
When the gear starts rotating by the rotation of sub-motor, the gear switch is switched from NC side to No side,
which makes the motor circuit opened between the'terminal. 18 and 20, and the main motor starts rotating.

AUTO PLAY

When the stylus of cartridge comes to the end of the disc grooves after the playing, the delivering arm moves rapidly
between the LED. and photo transistor.

When the voltage at the input terminal 3 in the operation amp. exceeds the voltage at the input terminal 2, the output of
operation amp. turns to be (+), and only the SCR2 works, which makes the sub-motor get one rotation.

The pick-up arm is returned to the arm-rest in the former half of rotation of the main gear.

As the solenoid does not rotate, the selector stops at the angle corner of the rotation plate, which does not make the
rotation plate rotate and the pick-up arm stops at the arm-rest. ~

When the pick-up arm gets back to the arm-rest, the rest switch is turned on, and the gear switch is switched to NC side,
which makes the motor circuit shorted between the terminal. 18 and 20 and the mian motor stops finally.

REPEAT PLAY

Like the AUTO PLAY mode, the SCR2 turns on, which rmkes the sub-motor get one rotation.

The pick-up arm is returned to the arm-rest in the former half of rotation of the main gear.

At the same time, the SCRl also turns on and the solenoid rotates either to the LP or EP side depending 0N speed
selector just as the case that PLAY switch is turned on.

The delivering arm rotates till the lead-in position of LP or EP, and repeat playing.

CUT
When the cut button is pushed in, only the SCRl works, and the solenoid does not rotate. Only the sub-motOr rotates,
the pick-up arm gets back to the arm-rest, and the main motor stops rotating upon its return at the AUTO mode.

PU arm up-down operation

When the lifter lever gets down, the main gear stops, and the lifter cam-plate goes down, and the pick-up arm is kept in
the down status, while the main gear rotates, the lifter cam-plate is lifted up by the main gear, and the pick-up arm is
kept in the up status