Panasonic SA-HT640WP, Service Manual

Page: 93 / 120

20.2. Basic Troubleshooting Guide for Traverse Unit
*Compare the above with OK condition
Module
Checking components
a) Check LD current
Checking Points
8) Jitter out of specification
Problems
b) Check OPU (change to other unit and
confirm)
*Check for solder short and/or component
damaged
IC8051
Q8550, Q8560, Q8561, Q8562
Q8550, Q8551, Q8552, Q8560
*Check for solder short and/or component missing
/ damaged
*Check for solder short and/or component
damaged
Q8550, Q8551, Q8552, Q8560, Q8561, Q8562
FP8201
IC8251
IC8251
Q8550, Q8551, Q8552, Q8560, Q8561, Q8562
IC8001
*Check for solder short and/or component missing
/ damaged
LB8301, R8321, R8322, LB8302, R8325, R8326
IC8421
*Check for solder short and/or component missing
/ damaged
a) Check laser drive circuitry (voltages and
current)
- Check CD laser drive
*Compare the above with OK condition
Module
- Check DVD laser drive
*Check voltages and LD current and
compare with OK Module
a) Check SDRAM address and data bus
signal
b) Check video signals
c) Check audio DAC circuitry
b) Check laser drive circuitry (voltages
and current)
c) Check LSI connection to motor drive
circuitry
*Compare the above with OK condition
Module
a) Check connection from Backend Module
to Traverse unit
b) Check motor driver circuitry on voltages
and control signals
*Compare the above with OK condition
Module
a) Check motor driver circuitry (voltages)
7) Block noise during play
- Cannot read CD
- Cannot read DVD
6) Cannot read disc but
spindle is spinning
3) Disc not spinning
4) Traverse not moving
5) Traverse and spindle
abnormal movement
2) No TOC/Long TOC
Checking components
1) Distorted picture or
abnormal sound is heard
during initialisation
Problems Checking Points
a) Check SDRAM addresand data bus,
CLK and other control signals waveform IC8051
93
SA-HT640WP / SA-HT640WPC