Pioneer PL-4 User manual

Service
PAL ETUIET
REPAIR
&
ADJUSTMENTS
ORDER
NO.
ART-709-0
STEREO TURNTABLE
L.—<}
PL-320
MODEL PL-4 COMES IN SEVEN VERSIONS DISTINGUISHED AS FOLLOWS:
Remarks
120V only U.S.A. model (Without cartridge)
120V only Canada model (Without cartridge)
220V — 240V Europe model
220V — 240V United kingdom model
220V — 240V Oceania model
110V—1 20V/220V—240V (Switchable) General export model
110V—120V/220V—240V (Switchable) U.S. military model
MODEL PL-320 COMES IN FIVE VERSIONS DISTINGUISHED AS FOLLOWS:
Voltage Remarks
220V — 240V Europe model
220V — 240V United kingdom mode!
220V — 240V Oceania model
110V—120V/220V—240V (Switchable) Generali export mode!
110V—1 20V/220V—240V (Switchable) U.S. military model (Without dust cover)
= This is the service manual for model PL-4/KUT. For servicing of the other types,
please refer to the additional service manual.
®= Ce manuel d’instruction se refére au mode de réglage, en frangais.
= Este manual de servicio trata del método de ajuste escrito en espajiol.
PIONEER ELECTRONIC CORPORATION 4-1. Meguro 1-Chome, Meguro-ku, Tokyo 153, Japan
U.S. PIONEER ELECTRONICS CORPORATION &5 Oxford Drive, Moonachie, New Jersey 07074, U.S.A.
PIONEER ELECTRONIC (EUROPE) N.V. Luithagen-Haven 9, 2030 Antwerp, Belgium
PIONEER ELECTRONICS AUSTRALIA PTY. LTD. 178-184 Boundary Road, Braeside, Victoria 3195, Australia
FU © APR. 1981 Printed in Japan

= For the circuit and mechanism descriptions, please refer to the supplement of model PL-7
service manual (ART-768).
CONTENTS
1. SPECIFICATIONS ...........2 000s eee 2
2. FRONT PANEL FACILITIES.............. 3
3. DISASSEMBLY ... 0... eee ee ee eee eee 4
4, TROUBLESHOOTING. ...........00 000 es 6
5. PRECAUTIONS FOR REASSEMBLY........ 10
6. BLOCK DIAGRAM.......... 00ers 12
7. P.C. BOARDS CONNECTION DIAGRAM..... 13
1. SPECIFICATIONS
Motor and Turntable
Drive System 1.0... eee teen eae Direct-drive
IMG BOF sister, ly ecncte te cabin, bes gris Sens Dhansel ROEUE, Cate Hen eee iets DC servo motor
Turntable Platter. .........310mm diam. aluminum alloy die-cast.
SPECS ye 865 suh fisidanctivns elhenttw oem Wamesianace6 Alea 33-1/3 and 45rpm
Wow and Flutter .............02 000 Less than 0.025% (WRMS)
Signal-to-Noise Ratio..............--. More than 78dB (DIN-B)
(with Pioneer cartridge model PC-3MC)
Tonearm
TY Dh are oes Aucune ee ecole Static-balance type, Straight pipe arm
Effective Arm Length ..........2--2 2200-2 eee eee 221mm
Overhang: escaped acess dow ogc Gee ert acs ale de aa 15.5mm
Usable Cartridge Weight ........-.-.. 3g (min.) to 8g (max.)
Subfunctions
Auto-return mechanism, Anti-skating force control, Stylus pressure
direct-readout counterweight, Cueing device, Strobe light, Free
stop hinges
Miscellaneous
Power Requirements. ........... 00 0 ee es AC120V, 60Hz
Power Consumption ...........000 0000 cece OW
Dimensions .............. 420(W) X 108(H) X 367(D)mm
16-1/2(W) X 4-1/4(H) X 14-7/16(D)in.
Weight 0 .'65 5.0. Sg iy ee vslare A gh Bla teen plete 5.8kg/12 ib 12 oz
2
8. SCHEMATIC DIAGRAM...............- 15
9. EXPLODED VIEWS .............-.00.0. 17
10. ELECTRICAL PARTS LIST.............. 22
11. ADJUSTMENTS. ..........00.- 2002 eee 23
REGLAGE. cal tyies cea uae naam 24
AIJUST Eee ie GGA Reh Ae eed Ea ee 25
12.:-PAGKING cc 8d 4s Saas ore whee ee 26
Accessories
EP Adapters 5.3.22 foes Se lense ce ek tee ee he WS Rte SEN ie 1
Operating Instructions... 2... ...0.0.0.00.000. 000 eee ee 1
NOTE:
Specifications and design subject to possible modification without
notice, due to improvements.
:
:
3
7
i
q
a
a
:
thigh a i i ir aS

2. FRONT PANEL FACILITIES
eS ®
eo ©
() CUT switch
Depress this switch to stop play.
(2) Speed check window
Look through this window and observe the movement
of the striped pattern when checking the rotational
speed or finely adjusting the speed. The position of the
striped pattern differs according to the power line
frequency (50 Hz or 60 Hz) in the area of use and the
speed (33 or 45 rpm) of the platter.
Top pattern: For 45 rpm in 50 Hz area
Second pattern: For 45 rpm in 60 Hz area
Third pattern: For 33 rpm in 50 Hz area
Bottom pattern: For 33 rpm in 60 Hz area
(3)SPEED ADJ control
Rotate this control in order to finely adjust the speed
of the platter.
The speed is reduced when the control is rotated in the
[- ] direction.
The speed is increased when the control is rotated in
the [+] direction.
(4) SPEED switch
Set
this
switch
in
accordance
with
the
speed
of
the
re-
cord which is to be played.
[33] (depressed position):
[45] (released position):
©) Cartridge
For 33-1/3 rpm records
For 45 rpm records
(6) Headshell
@ Tonearm
(8) ARM ELEVATION lever
Operate this lever when starting record play or when
temporarily suspending play.
@ ANTI-SKATE control
This is rotated when performing the anti-skating adjust-
ment.
Arm rest
This serves to hold and clamp the tonearm. When
moving the tonearm, release the clamp.
(}) Tracking force adjustment weight
This is used when adjusting the tracking force.
(2 Platter
(3) Platter mounting shaft
Rubber mat
(5) EP adapter
This is used when playing records without a ‘‘middle.”’
(16 Cabinet
(7) Dust cover

3. DISASSEMBLY
3.1 PANEL AND BASE
In removing the panel, follow the below listed
steps in the order given. Using any unnecessary
force will result in bending the springs or damaging
other parts.
Panel removal steps
1. Remove the headshell and weight assembly,
and the weight shaft assembly.
The weight shaft assembly is removed by
loosening screw (Hexagone socket screw)
and the headshell by loosening screw @ .
2. Lift off the turntable platter.
Turntable
platter
3.
AD oP
Panel
Motor —
assembly | |= Ae
| omen EN
Base
Dust cover
Loosen insulator attachment screws @ and
remove the insulator. (Do not mix the color-
coded float springs. They must be replaced
with their original insulators during reassemb-
ly.)
. Remove the rear panel PU cord strain relief.
- Unplug the 2P and 5P connectors.
. Completely remove the PU cord from the panel.
Lift up the headshell end of the tonearm,
and
taking
care
not
to
damage
the
tonearm,
remove it from the panel. (Hold the tonearm
steady.)
Weight assembly
Screw 8 Rubber bush
Control mechanism
assembly
Insulator
z
Fig. 3-1 Disassembly

3.2 D.D MOTOR ASSEMBLY
After the panel has been removed, loosen the
three motor attachment screws @ and remove
the motor.
3.3 TONEARM SECTION
Remove the tonearm section by taking out the
three arm base attachment screws @ and one
ground wire securing screw@.
3.4 CONTROL MECHANISM SECTION
After the tonearm section has been removed,
loosen the three control mechanism attachment
screws @and remove the assembly.
Tonearm
PU plate
Fig. 3-3 Remove tonearm
3.5 TONEARM
1. Disconnect the tonearm lead wires from the
PU board (See Fig. 3-2).
Note that some of the lead wires have been
soldered to the PU board, and must be discon-
nected with care.
2. Loosen the set screw @ with a screwdriver to
remove the PU plate under the arm base (See
Fig. 3-3).
8. Undo the screw @ securing the tonearm to the
arm base (See Fig. 3-3).
Tonearm
lead wires
PU board Red
Fig. 3-2 Disconnect the tonearm lead wires
(Hexagone socket screw)
Arm base

4. TROUBLESHOOTING
Use the following directions to find the cause of
each type of breakdown. Improperly adjustment
units should be completely readjusted.
« AUTO-RETURN DOES NOT WORK
Change in starting position adjust-
ment.
Starting plate does not follow the NO Too much grease between the signal
signal plate. plate and the cam
YES
YES
Inner diameter of the starting plate
hole is small.
Protrusions on the caulk section of
the starting plate hole.
Not enough grease between the
starting plate and signal plate.
After starting, incomplete reset of the NO The curved section of the signal
signal
plate.
(See
Section
1)
plate
is
deformed.
YES
Arm lead wire is caught on something.
PU cord is touching the PU plate.
The inner areas of records can not
be tracked.
Operator of the detection lever is
not smooth.
Looseness in the PU plate attach-
ment.
Section 1
After performing the return operation, if the
curved section of the signal plate and curved sect-
ion of the starting plate are not in contact with
surfaces
A)
and
respectively
of
the
cam,
reset
will
be
incomplete
and
the
starting
position
will
be late. As a result, the return function may not
operate at times. In this case, bend the signal
plate ©)so that dimension (A) is 0.5mm or larger. Cam
Fig. 4-1 Incomplete reset of starting and signal plates.
Starting plate
: At least 0.5mm
0
see ee IS it Bae Lay ot a a

=» RETURN IS FAST (RETURN AT 1mm PITCH)
Protrusions on the pinion gear section
(See section 2)
Section
2
Pinion
gear
If
there
are
rough
areas
of
plastic
protruding
Protruding
section
from the (A) section of the protruding section of
the pinion gear, the return function may operate
at
a
pitch
of
only
1mm.
In
this
case,
remove
the
Fig.
4-2
Elimination
of
pinion
gear
protrusions
plastic protrusions completely (Fig. 4-2)
» MOTOR DOES NOT ROTATE
2P and 5P connectors are not attach-
ed.
YES
Connector(s) is not properly installed.
= MOTOR DOES NOT STOP
The switch lever and switch locker No The installation location of the PU
are not locking (See section 3) plate is incorrect.
Section
3
|
PU plate
In order to turn the power OFF, the PU plate
shaft touches surface ® of the switch locker
pushing it over so it locks with the switch lever
turning the microswitch OFF (Fig. 4-3). If
the amount of push on the switch locker is insuf-
ficient, it can not lock with the switch lever.
With the tonearm locked in the arm rest, as shown
Switch lever |
in figure 4-4, attach the PU plate precisely mid- Mads rel Peers Gr switch Iocker
way between the first and second points from the
arm base scale mark counting away from you. Pte:
Arm base
scale mark
Fig. 4-4 Adjustment PU plate

« MOTOR ASSEMBLY
NOTE:
The IC PA2008 used in the PXM-090 does not have a dedicated ground pin for
its internal circuitry, but uses the thermal fan ground. When replacing the IC, make
sure the securing screws retaining the ground line between the IC and thermal
dissipator and between the thermal dissipator and motor base, and base to circuit
board is securely tightened.
e Motor Does not Turn
are
Component
connected
to
Is Vee 1 29 volts? Me rh supply circus detec: PA2008 terminal 4 defec-
YES : tive.
LA ane eae term NG PA2008 defective. NO
YES
Is PA2007 terminal 11 less |no | PA2007 defective or parts Poor PA2008 Tab terminal
than 3.5 volts? connected to PA2007 to GND contact.
YES
terminal 11 defective.
Is
PA2008
terminal
3
|NO
PA2008
defective
over
1.0
volt?
;
® Motor Does not Stop
Hall element defective or
Hall element bias resistor
defective.
Is Hall voltage DC bias Ha:
15-17 volts; Hb; 4-6
volts:
When the motor is rotated
by hand, is Hall voltage
(Ha, Hb) generated?
If resistance is high, coil
wire is open; if resistance
is low, PA2008 is defective
or coil is shorted.
R5_ defective or printed
circuit open.
With power OFF, is DC
resistance between PA2008
terminals 12—14 and 1—13
60 ohms?
With power OFF, is DC
resistance between PA2008
terminals 7—2 3.9 ohms
YES
PA2008 defective.

e Motor Runs away
Is
Vee
1
29
volts?
NO
Power
supply
circuit
de-
fective.
YES
:
—
|NO
NO
Is
PA2008
terminal
4
10
PA2008
defective.
Parts
connected
to
PA2008
11
volts?
terminal
4
defective.
YES
: :
NO
Is
FG
signal
input
to
?
PC
pattern
open
in
FG.
YES
Parts connected to PA2007
;
NO
serie
oir
i
to
terminal
13
defective
or
PC
ermina
‘
pattern
open.
YES
PA2007 defective or parts
connected to PA2007
terminal 14 defective.
Is FG signal output from
PA2007 terminal 14 over
12V p-p?
NO
YES
Slow down the motor at
about 33 1/3 rpm with a ;
hand, is the prescribed NO PA2007 defective or Cl
defective.
waveform output from
PA2007 terminal 4?
YES
Slow down the motor at
aoe 33 1/3 rpm Wes a |No PA2007 defective or C3
hand, is the prescribed :
defective.
waveform output from
PA2007 terminal 1?
YES
PA2007 defective, or C2
defective, or parts connect
When the motor is stopped
by hand, is the output
Is the potential between
PA2007 terminal 5-6
0.5—0.8
volts?
between
PA2007
terminal
5-6 defective.
from PA2007 terminal 11
less than 3.5 volts?
YES
PA2008 defective.

5. PRECAUTIONS FOR REASSEMBLY
Follow these directions and precautions when
reassembling a unit after completing repairs. Be
sure to lubricate as required, make no mistakes
when attaching parts, and avoid all other careless
mistakes that may be the cause of trouble later on.
5.1 AREAS THAT REQUIRE LUBRICATION
NOTE:
Types of lubricants and areas where they are used are
listed in table 1.
Table 1
Areas used
Type of Oil
Silicon Oil #50000 raising shaft
GYA-008 all other areas
Lubrication points are specified for oils other
than GYA-008. Never use a different type of oil.
e Cam Section
Apply oil to the heart-shaped grooved section
(rear side of the cam) and lock plate sliding section
in order to minimize wear on the sliding section
and the burden on the mechanism.
e Driving Plate Assembly
Decrease the burden on the mechanism and the
wear on the sliding section.
Sides, top, and bottom surfaces
e (sliding section of auto-stop
S mechanism)
Sides surface
(sliding section of
auto-stop mechanism)
Top and side
EV cam side surface
(sliding section of elevation cam)
Fig. 5-1 Driving panel assembly section switch locker section
¢ Switch Locker Section
Apply oil to the switch locker (opening) and
sub-panel base sliding section to decrease the
burden on the mechanism.
When applying oil to the opening (shaft hole),
do not apply any oil 2—3mm from the bottom
surface. If oil is applied 2—3mm within the
bottom surface, it may come out the bottom and
go between the switch lever and sub-panel base
causing the switch lever to operate ineffectively.
10
Switch locker
Fig. 5-2 Switch locker section
e EV Lever Unit Section
Apply oil to the sliding section of leaf spring
(A) and EV lever unit to decrease the burden on
the mechanism.
Leaf spring (A)
sliding section
EV lever unit
4 EV lever unit
sliding section
| cane
\ Arm base
\
Fig. 5-3 EV lever unit section
e Elevation Cam Section
Apply oil to the elevation cam and sliding sec-
tion of the raising shaft to decrease the burden
when operated.
Elevation cam
Fig. 5-4 Elevation cam section
e EV Sheet Section
Apply oil to the raising shaft and sliding section
of the bearing to assure stability in the elevation
lowering speed.
eit ee i Sas) Sin et,