Technics SL-PJ28 - Page 14

i TROUBLESHOOTING GUIDE
No CO playback
Does the test NO
disc rotate? =:
YES
Check if TOC NO
reading is performed.
Does “PLAY” appear
on the display? Betow 700 mV
_ ornooutput 7
<“Check output at
pin @ of CP701
Playing time appear on the display
At about 1 Vp-p
ts pin @ of 1C706
at "HIGH" or “LOW”?
Is pin@®
of CS702 at “HIGH”
or "LOW"?
is there an output
at pin @ of 1C7047
10706 failure OK
ou”
NO
1 Check the
No waveform or upper and
lower amplitudes are
not equal. Check pin@ >>
: of 10701.
Upper and lower
amplitudes of
waveform are equal.
Optical pickup :
failure 1C701 failure
ts pin @ of IC704
at “HIGH” or “LOW"2
Is pin © of CS702
at "HIGH" or “LOW"2
4 2
Tum on close Above 0.4 V gy
“wn switch (S790) ——
Optical pickup
1€704 failure) | 1C706 failure
Remains at
SL-PJ28 — SL-PJ28
Turn on close switch (S790)
Does optical pickup ~ NO
' Optical pickup moves toward
inner track once, and then toward
outer track slightly (2 or 3 mm).
Check the position At outer or around middie track
of optical pickup.
At inner track
ts pin @ of CS702 tH” LY
1s pin ® of CS702 a
at “HIGH” or "LOW"? eS
“HIGH” or “LOW”
Are there outputs
at pins © and @ of
1€703?
Does
laser
diode
NO
“L"
(OV)
come
on?
Inner
track
rit
Inner
track
limit
switch
NES
switch
is
defective
aac
aas
failure
or
disconnected
i
Load
the
testdise
Are there outputs
ts there an output
pins @ and @ of
at pin @ of IC7047
failure
Traverse deck
{C704 failure {C703 failure failure
“H" Check pin @ of
1C701 Above 0.6 V Measure voltage
between © and ©
of Q701.
Changes from is there an output
“H
to
“L”,
Below
0.6
V
at
pin
@
of
1C704?
Remains at
SH" Check pin @ of
cs702
1C704 failure 1C703 failure
Changes from
“H" to “L",
Q701 or optical
10704 failure 1C702 failure pickup is (C701 failure
defective.