Sansui CD-E770 - Page 9

CD-E770
3. TROUBLESHOOTING
3-1 . Disk Loaded, but No Track Count or Performance Time Displayed
(Cannot Read T.O.C.)
Is the disk ciamped correctly?
Is the pick-up in the read-in position?
YES
Is
laser output executed?
YES
Does the lens move up and down?
NO
NO
NO
NO
YES
f
NO
C
wlC3(CXA1082AS) and
wlC(STA341)faulty
Is the disk motor functioning?
YES
I)
NO
Goto©on'page 9.
f
YES
Is
there a focus error output at TP2 or TPF1 ?
NO
* Ground TPF2. When plek up
CXI
082AS is operating,
an sine wave is output from
TPF1.
YES
Faulty RF amp IC fIC 1
CXA1081S.
3.8Vp-p
~ 5 ms/ DIV
OK
NO
Does focus
turn ON?
• Does the output from
pin 9 (SENS) of wlC3 (CXA1082AS)
change
as follows; "L"->"H"-»"L"->pulse?
YES
YES
H Pulse
inuuuu
1.2Vp-p
10m/s
NO
Go to @ on page 9.
"Check mounting of tray.
Check loading mechanism.
Check clamping mechanism.
Faulty pick-up feed.
Check the feed mechanism and
slide (feed) motor circuit.
• wlC3 (CXA1082AS) pin 20 (SLD)
output: operating: ±1 v stopped: 0.6V
•wlC1 (STA341) pin 6 (JP5, pin 5)
output: operating: ±0.4V stopped: OV
• Check operation of slide motor.
. • Faulty microprocessor
Does the level of
pin 30 (LDON) of
microprocessor wlC6
(CXP-5034H) change to "L"?
Does the level of pin 5 (LD) of
fICI (CXA1081) change to "L"?
•fQ1:ST0Pi
ON
E 5V, C 1.4V, B 4.4V)
E 3.6V, C 2.4V, B 3V)
IFlow the current for operating the laser diodëT
• Is the focus search voltage output?
• Is there any output at pin 11 (FOC) of
wlC3(CXA1802AS)?
Change from +2V to about -2.5V.
• Is the focus drive voltage outout?
• Is there any output at pin 8 (TP3, TO) of
wICI (STA341)f
(6 )
YES
Faulty laser pickup or faulty connector JP2.
Does the focus search turn ON?
• Does the level of pin 28 (FOK) of fICI (CXA1081S)
change to
"H"?
NO
• Is there a laser output at the laser pickup?
(check using the laser
power meter)
• Is there continuity with the laser pickup focus coil?
JNO
Faulty laser pickup.
Check the
laser pickup output.
• Is there any output at TP1 RR When focus
does not
turn ON.
/ \P
/ \-L 5ms/DIV
Eye-pattern
output with focus ON.
Faulty
wlC3 (CXA1082AS)
Faulty focus adjustment.
• Move the focus offset adjuster to lts mid point,
then slowly adjust it.
_ • Focus gain adjustment.
8