Panasonic RX-DT505 Service Manual page 35

m TROUBLESHOOTING GUIDE
No CD playback
Does the test NO
RX-DT505 RX-DT505
disc rotate?
Check if TOC NO
Remove the test disc
Turn on close switch 200
reading is performed.
NO
Does optical pickup
move?
Optical pickup moves toward
inner track once, and then toward
outer track slightly (2 or 3 mm).
Check the position At outer or around middle track
of optical pickup.
on the display?
Playing time appear on the display
Are there outputs
at pins ©, @ and @
of 1C705?
@ LRCK
@BCLK {0K
@ SRDATA
Is pin®
of CS702 at "HIGH"
or "LOW"?
Are there outputs
at pins @ and @
of CS702?
| IC705 failure
OK _"H"
Check the
; 1C706 failure
unit
No waveform or upper and
Py lower amplitudes are
not equal.
Below 700 mV
or no output
Does lens make
vertical movements?
Check output at
pin @ of CP701
YES
Is pin @ of CS702
Is pin @ of CS702 at
at "HIGH" or "LOW"?
"HIGH" or "LOW"'?
At about 1 Vp-p
Are there outputs
at pins © and @ of
1703?
Does laser diode "L? (OV)
come on?
NO
Is pin 62 of IC706
at "HIGH" or "LOW"?
Is pin @ of IC704
at "HIGH" or "LOW"?
Inner track limit
switch is defective
or disconnected
Inner track limit switch
is short-circuited.
YES Optical pickup
failure
Measure voltage
across R701.
Below 0.4 V
Load the
test disc
Is pin @ of CS702
at "HIGH" or "LOW"?
Is there an output
at pin @ of IC704?
Are there outputs
pins @ and @ of
1C703?
Is there an output
at pin @0 of IC704?
Furn on close Above 0.4 V
switch (S790) ; :
Optical pickup
failure
Check pin @ of
1C701
Traverse deck
failure
R711 failure 1C704 failure
IC704 failure IC703 failure
1C706 failure
Remains at
"HP
Measure voltage
between © and ©
of Q701.
Above 0.6 V
Charges from
"H" or "L". Below 0.6 V
Is there an output
at pin @ of 1IC704?
Remains at
Check pin @ "H" Check pin © of
of IC701.
1C704 failure IC703 failure
Upper and lower Changes trom
amplitudes of "HY or "L".
waveform are equal.
Optical pickup
failure