Panasonic SA-HT640WPL, Service Manual

Page: 95 / 122

20.2. Basic TroubleshootingGuide forTraverse Unit
*Compare the above w ith OK condition
Module
Ch ecking components
a) C heck LD curr en t
Ch eckin g Points
8) Jitter out of specification
Prob lems
b) Che ck OP U ( cha nge to othe r uni t a nd
co nfir m)
*Check f or solder short and/or component
damaged
IC 8051
Q8550, Q8560, Q8561, Q8562
Q8550, Q8551, Q8552, Q8560
*Check f or solder short and/or component missing
/ damaged
*Check f or solder short and/or component
damaged
Q8550, Q8551, Q8552, Q8560, Q8561, Q8562
FP8201
IC 8251
IC 8251
Q8550, Q8551, Q8552, Q8560, Q8561, Q8562
IC 8001
*Check f or solder short and/or component missing
/ damaged
LB8301, R8321, R8322, LB8302, R8325, R8326
IC 8421
*Check f or solder short and/or component missing
/ damaged
a) C heck la se r d riv e circ uit ry (vo lta ge s a nd
cu rre nt)
- C heck CD la se r d riv e
*C om pa re th e ab ov e wit h O K co nd iti on
M odul e
- C heck DV D la se r d riv e
*Check voltages and LD current and
compare with OK Module
a) Che ck SD RA M a ddre ss and da ta bus
sig na l
b) Che ck vide o s ign als
c) C heck au dio DA C ci rc uit ry
b) C heck la se r d riv e circ uit ry (vo lta ge s
and cu rre nt)
c) C heck LS I co nn ectio n t o m oto r d riv e
cir cui try
*Compare the above with OK condition
Module
a) C heck con nect io n f ro m B ack end M od ule
to Traverse unit
b) C heck mo to r d riv er ci rc uit ry on vo lta ges
and co ntro l signals
*Compare the above with OK condition
Module
a) C heck mo to r d riv er ci rc uit ry (vo lta ge s)
7) Block noise during play
- Cannot read CD
- Cannot read DVD
6) Cannot read disc but
spindle is spinning
3) Disc not spinning
4) Trav erse not mo ving
5) Trav erse and spindle
abnormal movement
2) No TO C/Long TO C
Ch ecking components
1) Distorted picture or
abnormal sound is heard
during initialisation
Prob lems
Ch eckin g Points
a) Ch eck SD RA M addresand data bus,
CLK and ot her control signals waveform
IC 8051
95
SA-HT640W PL