Technics SL-PS670A

M@ Troubleshooting Guide
No CD playback
Does
the test disc
rotate?
YES
NO
Check
tt TOC reading is
performed
NO
NO
output at of TJ701
(RF)
PLAY” appear on
he display? At about 0.5 Vp-p
Playing time appear
on the display
“>
66)
“HIGH” or “LOW”?
Are there
Outputs at pins @)
@ and @) of
1C702?
@ BCLK
@ LRCK OK
@ SRDATA
NG
an output at pin
@6 of |C702?
(KICK)
OK
OK
1C702
failure
Are there
outputs at pins
@3)and (75) of
1C702? Are there
Outputs at pins 49
NO and @0 of
IC703?
OK
1C702 failure Check the unit 1C702 failure
Optical pickup
failure
Zz
i |
1C703 failure
No waveform or upper
he and lower amplitudes
are not equal.
Check
pin @ of IC701
(FEOUT)
Without Upper and lower
2.5 V+1.25V s there amplitudes of
limit. an output at pin waveform are equal.
9 of IC7027
(FBAL)
Within
2.5V+1.25V
limit.
Optical pick
1C702 failure ‘ate 1C702 failure
207
SL-PS670A
SL-PS670A
Remove the test disc
Turn on close detect
switch (S782)
Does
optical pickup
move?
NO
Optical pickup moves toward inner
track once, and then toward outer
track slightly (2 or 3 mm).
lens make vertical NO
ovements?
YES
Does NO
laser diode
come on?
YES
Load the test disc
Turn on close detect
switch (S782)
Remains
at “H”
Check
pin @) of |1C701
(RFDET)
Changes from
“H tol”
Changes from
“H" to “L”
Remains
at “H” Check
pin @ of IC702
(FLOCK)
1C702 failure
voltage across
Q751 or optical
pickup is defective
1C701 failure
Outputs at pins @1)
and @ of
1C703?
Optical pickup
failure
Below
Is there
an output at pin
@ of IC702?
FOD)
OK
1C703 failure
R752
Above 0.4 V
1C702 failure
Remain at 2.5 V
(High impedance)
Is there
an output at pin
@ of |C702?
ECM
Changes from
2:5 V toi“?
(High impedance)
1C708 failure
1C702 failure
At outer or around
middle track
Check the
position of optical
pickup
At inner track
Is pin
~ “HIGH” or
“LOW"?
“L’ (0 V)
Inner track limit switch
is defective or
disconnected
outputs at pins
4?) and 4) of
C703?
Traverse deck
failure
s there
an output at pin
@ of |C702?
(TRV)
1C702 failure 1C703 failure
So