Symptom 3: Plays Cd But Not Dvd Discs - Sony DVP-S300 Training Manual

Second Generation DVD
The second generation DVD players consist of models DVP-S300, DVP-
S500d, DVP-C600d and DVP-S7700.

Symptom 3: Plays CD but not DVD discs

Cause: There are three common reasons that the player will only PB CDs:
1. The laser beam must be perpendicular to the disc. This is critical
when reading fine pitched DVD discs, but not for CDs. Therefore if
the tilt servo is not working, CDs will still play but not DVDs. Inspect
the Laser base unit for a crack in the plastic preventing tilt.
2. The laser assembly may have low output. As the laser output de-
creases with use, the RF eye pattern decreases in amplitude causing
skipping, and finally no DVD playback.
3. The spindle motor must turn faster when playing a DVD. As the motor
brushes wear down, the torque at the high speed cannot be main-
tained and the DVD does not reach the normal operating speed.
4. Corrupt EEProm data.
Repair procedure
1. Inspect the plastic base unit holder (DVP-S500d ref. #263) for cracks
that prevent the laser assembly from tilting.
You can also operate the tilt mechanism from the test mode under
section "Manual Adjust 2" for inspection. With the player OFF, press
the remote control TITLE, CLEAR, and then the POWER button to
enter the test mode. Using the number buttons, select 2 Drive Manual
Operation, 5 Manual Adjust, then 2 Tilt Offset. After remembering the
original offset number, use the arrow buttons to change the offset
number and drive the tilt motor. As the motor turns, the laser assem-
bly should be mechanically tilting. Return to the original offset number
before exiting (exit by pressing the power off button).
2. On the MB-78 board monitor, check connector CN303/pin 1 for a RF
(eye pattern) signal when trying to play a DVD. The normal signal
level here is 1.2Vp-p. As the laser ages, this level decreases. Skip-
ping occurs when the level drops to approximately 0.9Vp-p. No disc is
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detected when the RF level drops lower than 0.9Vp-p. Even when no
disc is detected at slightly below 0.9Vp-p, a DVD may still play in the
test mode, producing only a low amplitude eye pattern. No picture
appears when the servos are individually (manually) turned on for PB
in the test mode. See the Test Mode section of this book for further
information.
3. If the laser assembly tilts and the RF starts at 1Vp-p (minimum) be-
fore shutdown, the spindle motor could be worn. Replace the spindle
motor if the RF signal is above 1Vp-p (laser is OK). Sometimes a
defective spindle motor shows up in the test mode when the unit in-
correctly identifies a 12cm DVD as an 8cm disc when attempting to do
the DVD drive adjustments. Enter the test mode and select: 2 Drive
Manual Operation, 0 Disc Type, and 5 Disc Type Check.
4. The EEProm data may be defective but can be reset to default user
and service values from the Test Mode. After the default values are
entered, the player must be aligned. The procedure for resetting the
EEProm is as follows:
•
Access the Test Mode by pressing Title, Clear, then Power buttons.
•
From the Test Mode Menu, press 2. Drive Manual Operation
•
From this sub menu select 7. Check for the memory access.
•
Select 1. EEProm Default Set
•
Press RETURN several times to go back to the initial Test Mode Menu
to begin automatic alignment.
•
Select 1. Drive Auto Adjustment and follow the directions to adjust tilt,
focus and tracking sections.