Technics SL-220 Service Manual

@ CHECK POINTS
(A) Switching on does not cause turntable to rotate
1) Check the line power circuit
2) Check for 12V DC between @ - ©
a) Replace speed selector switch
b) Solder securely
3) Check speed selector switch
a) Faulty contact b)Soldered improperly|
4) Check VR1, VR2, VR3 or VR4 a) Replace VR1, VR2, VR3 or VR4
a) Faulty b) Soldered improperly b) Solder securely
ox
5) Separate motor and the F.G. SERVO P.C.B
6) Confirm that motor rotates with 5V DC applied between the red lead |BAD
(Positive) and the blue lead (Negative) separate source and see that the Replace’motor
noload is about 20mA
Replace F.G. SERVO P.C.B.
Turntable rotates abnormally
i hi
1) Adjust VAI, VR2, VRS or VR4 When the strobe dots appear to be stationary, the speed
STILL ABNORMAL
a) Replace VR1, VR2, VR3 & VR4 or speed selector switch
b) Solder securely
(B)
3) Check VR1,VR2, VR3 & VR4 or speed selector switch |BAD)
a) Faulty contact —b) Soldered improperly
OK
4) Check for 12V DC and a ripple voltage of [BAD] Check ripple filter and diodes
about 0.5Vp-p between @- © If faulty, replace
[B)Separate motor and the F.G. SERVO P.C.B]
6) Connect a separate 5V DC power supply between the red lead (positive) BAD
and the blue lead (negative) of the motor.
Motor should rotate. Connect oscilloscope between the white lead
(positive) and the red lead (negative) of the motor.
Confirm that thare is about 120mVp-p.
Replace motor
7) Replace F.G. SERVO P.C.B.

Technics SL-220 Specifications

General

Drive System	Belt Drive
Speeds	33 1/3, 45 rpm
Wow and Flutter	0.045% WRMS
Dimensions	430 x 130 x 375 mm
Type	Semi-automatic
Motor	DC motor
Effective Length	230 mm
Overhang	15 mm
Platter	Aluminum Die-cast
Tonearm Type	Static balanced tubular arm
Cartridge Weight Range	6g