SONY - DVP S300_DVP S500D_DVP C600D_DVP S7700 _ Play CDs, but no DVDs _ Repair Help.

Cause:

There are four common reasons that the player will only playbacks CDs

• 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.
• The laser assembly may have low output. As the laser output decreases with use, the RF eye pattern decreases in amplitude causing skipping, and finally no DVD playback.
• The spindle motor must turn faster when playing a DVD. As the motor brushes wear down, the torque at the high speed cannot be maintained and the DVD does not reach the normal operating speed.
• Corrupt EEProm data.

Repair Procedure

• 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 assembly should be mechanically tilting. Return to the original offset number before exiting (exit by pressing the power off button).
• 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. Skipping occurs when the level drops to approximately 0.9Vp-p. No disc is 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.
•  If the laser assembly tilts and the RF start at 1Vp-p (minimum) before 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 incorrectly 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.

     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:

1. Access the Test Mode by pressing Title, Clear, then Power buttons.
2. From the Test Mode Menu, press 2. Drive Manual Operation
3. From this sub menu select 7. Check for the memory access.
4. Select 1. EEProm Default Set
5. Press RETURN several times to go back to the initial Test Mode Menu to begin automatic alignment.
6. Select 1. Drive Auto Adjustment and follow the directions to adjust tilt, focus and tracking sections