Technics
Quartz Direct Drive automatic turntable system SL-L2[M] – troubleshooting, disassembly,
mechanical and electrical adjustments
How to remove turntable platter
Open
the upper cabinet.
Remove
the turntable mat, and lift the turntable platter.
{when removing turntable platter, it is not necessary to remove the 45rpm
adapter. The turntable platter is tightly fitted to the center spindle.
When removing it, take care not to damage the upper cabinet.}
To
remove the dust cover,
Remove
the terminal solder by using a solder sucker.
Hold
the Hall element with tweezers and remove it while touching the soldering iron
to the terminal.
(Fit the hall element with the part number Print “UP”).
How to remove the tonearm.
Remove
the dust cover.
Remove
the shield cover setscrew.
Unsolder
the 5 lead wires.
Turn
the worm gear with your fingers to remove the tonearm inward.
To
remove the offset angle detection circuit board.
Remove
the indicator cover setscrew.
Remove
the indicator cover.
How to remove the arm dirive motor.
Remove
the dust cover.
Remove
the two setscrews.
Unsolder
the two lead wires from the motor.
Open
the cushion rubber.
How th remove the stylus set-down position volume circuit board
setscrew.
Remove
the cover.
Remove
the stylus set-down position volume circuit board setscrew.
How to remove the reset switch.
Remove
the screw.
Remove
the two claws of the switch holder.
Unsolder
the two switch terminals.
[when
replacing the reset switch, be sure to open the upper cabinet]
How to set the tonearm drive chord.
Remove
the dust cover and tonearm cover.
Remove
the roller cover.
Set
the chord in the order of steps 1 to 6.
Fit
the chord connector to the tonearm.
Set
the roller cover and turn the worm gear by hand to see the torn am moves.
How to remove the 45 rpm adapter.
The
two adapter claws fit into the turntable platter. Remove the 45rpm adapter by pushing by pausing it in.
[when removing the 45rpm adapter, remove the turntable platter;
otherwise the adapter claws will be broken.]
How to remove turntable platter.
Open
the upper cabinet. Remove the turntable mat, and lift the turntable platter.
[when removing the platter, it is not necessary to remove the 45rpm
adapter. The turntable platter is tightly fitted to the center spindle. When
removing the platter, take care not to damage the upper cabinet.
How to remove the bottom board.
Turn
over the unit on a soft cloth.
Remove
the six screws.
How to remove the power switch.
Remove
the three screws.
Lift
the holder slightly.
Pull
out the power switch.
How to remove the Hall element.
Remove
the terminal solder.
Hold
the Hall element with a tweeter and remove it while touching the soldering iron
to the terminal.
How to use the repair table.
Remove
the bottom board.
Remove
the operation circuit board and connect the PCB ground terminal to the chassis
(stator frame).
Put
the unit on the repair table.
Fit
the turntable platter and put the turntable mat.
Put
on the record and check the circuit from under the unit.
How to raise the set.
Turntable
platter is not fixed on the center spindle. {Take care so that the platter will not come loose. Take care allow the
set the set to fall down}
Remove
the bottom board.
Completely
open the upper cabinet.
Hold
the reset switch (cabinet) with the tape.
Fit
the turntable platter.
Raise
the unit and check the circuit.
How to turn over the set.
The
purpose is to check the voltage of each circuit point during stop of the
turntable.
Remove
the turntable platter and turn over the unit.
Remove
the bottom board.
Turn
the power switch ON and check the voltage.
How
to remove the cartridge.
Open
the upper cabinet.
Remove
the setscrew and pull out the cartridge.
[when attaching the cartridge, match
the tonearm connector with the cartridge pin, and completely insert it and
tighten the setscrew.]
Adjustment points.
Turntable drive control schematic
Troubleshooting Measurements and adjustments
Start position:
Open
the upper cabinet and put on the record.
Turn
the power switch ON.
Push
the Start switch.
Turn
the start position adjusting screw. If
it descends between tunes, turn it counterclockwise.
Clock frequency:
Connect
the lead wire with clip to IC301 29pin of operation circuit board.
Connect
the scope to IC301 8pin.
turn
the power switch ON.
Adjust
VR301 so that the cycle of the output waveform is 1.6msec +/-0.06msec.
Sensor gain:
Connect
DC voltmeter to IC401 12pin + and Ground.
Put
on the record for adjustment with A side up.
Turn
the power switch ON.
Torn
arm is on a between songs gap [blank area of the record]
Adjust
VR401 so that the output voltage is 8.5 +/- 0,3v.
Sensor resolution:
Connect
the Scope to the IC401 9pin + to ground.
Put
on the record for adjustment with slide A up.
Turn
the power switch ON.
Keep
the ‘F’skip switch depressed to move the tonearm. (output is delivered between
tunes is 3.0 +/- 0.3v).
Stylus
cue-down position:
Open the upper cabinet and hold the cabinet switch with
tape.
Put
on the record for adjustment with side B up.
Close
the upper cabinet.
Connect
the unit to amplifier (connect the speakers to the speaker terminals)
Turn
the power switch ON.
Press
the ‘F’ skip switch twice and then press the start switch.
After
completion of cueing, again press the ‘B’ skip switch to cue down.
Make
sure about the descending position after this adjustment.
Tonearm offset angle:
Remove
the dust cover.
Open the upper cabinet and hold the cabinet switch with tape.
Close
the upper cabinet.
Put
on the record.
Turn
the power switch ON.
Keep
the ‘F’ skip switch depressed to move the tonearm.
Turn
the adjusting screw so that the arm center matches the V-groove of the lift
bar.
Servo gain and offset voltage:
Remove
the dust cover.
Open
the upper cabinet and hold the cabinet switch with tape.
Connect
the DC voltmeter to CN301 5-pin + and Ground.
Remove
the sensor cover.
Turn
the power switch ON.
Keep
the ‘F’ skip switch depressed to move the tonearm.
Open
the upper cabinet.
Completely
shift the tonearm to the left, and then adjust VR501 so that the voltage is
6.0V[servo gain].
Set
the tonearm to the center and make sure that the output voltage is 3.0v.
If
the voltage is not 3.0v, adjust the set screw, so that the output voltage is
3.0v [offset voltage].