Basic Troubleshooting Guide For Traverse Unit (Main P.c.b.) - Panasonic SA-XH201GW Service Manual

10.3. Basic Troubleshooting Guide for Traverse Unit (Main P.C.B.)

Problems
1) Distorted picture or
abnormal sound is head
during the initialization
2) No TOC/Long TOC
3) Disc not spinning
4) Traverse not moving
5) Traverse and spindle
abnormal movement
6) Cannot read the disc but
spindle motor is spinning
- Cannot read CD/DVD
7) Block Noise during play
8) Jitter out of specification
Checking Points
a) Check SDRAM address, data
bus, CLK and other control signals
waveform
b) Check video signals (CVBS)
c) Check audio DAC circuitry
* Compare the above with OK
condition DVD Module P.C.B
a) Check motor driver circuitry
(VCC PVCC)
b) Check laser drive circuitry
(Voltages & current)
c) Check LSI IC connection to
motor drive circuitry
a) Check connection from Main to
Traverse unit
b) Check motor driver circuitry on
the voltages and control signals
a) Check laser drive circuitry
(voltages and current)
- Check CD Laser Drive
- Check DVD Laser Drive
* Check voltages and LD current
and compare with OK condition
Main P.C.B.
a) Check SDRAM address and
data bus signal
a) Check LD current
b) Check OPU
(Change to other unit and
confirmed operating condition)
42
Checking components
IC8051
LB8317, R8325, IC8011 (Pin 63)
LB8422 till LB8428
*Check for solder short and/or
component missing/damaged
IC8251 Pin 8, (+9V), 19 (+5V)
Q8552, CL8532 (For DVD),
Q8562, CL8530 (For CD)
IC8001 Pin 90, 93, 94, 95
IC8251 Pin 11 to 18
* Check for solder short and/or
component missing/damaged
FP8251
IC8251
* Check for solder short and/or
component damaged
Q8552, LB8551
(For DVD Laser Drive current)
Q8562, LB8561
(For CD Laser Drive current)
IC8051
OPU Unit (Traverse unit), FPC
connection (FP8531 & FP8251)