SONY DE251
Service Manual

SECTION 1 SERVICE NOTE
� NOTES ON HANDLING THE OPTICAL PICK-UP BLOCK OR BASE UNIT The laser diode in the optical pick-up block may suffer electrostatic breakdown because of the potential difference generated by the charged electrostatic load, etc. on clothing and the human body. During repair, pay attention to electrostatic breakdown and also use the procedure in the printed matter which is included in the repair parts. The flexible board is easily damaged and should be handled with care. � NOTES ON LASER DIODE EMISSION CHECK The laser beam on this model is concentrated so as to be focused on the disc reflective surface by the objective lens in the optical pick-up block. Therefore, when checking the laser diode emission, observe from more than 30 cm away from the objective lens. � To Check the Laser Diode and Focus Search Operation Open the upper panel. Turn on the power without a disc while the main board S801 (OPEN) is ON (or TAP802 is shorted). Then, observe the objective lens and check that the following operations are performed. 1. Scatterd light of laser beams is seen. 2. Check for vertical movements (five) of the objective lens (with movement of the PU on the inner circumference).
� MAIN BOARD � (SIDE A)
L401

� Before Replacing the Optical Pick-Up Block Please be sure to check throughly the parameters as par the �Optical Pick-Up Block Checking Procedures� (Part No.: 9-960-02711) issued separately before replacing the optical pick-up block. Note and specifications required to check are given below. � FOK output : IC601 eg pin When checking FOK, remove the lead wire to disc motor. When checking FOK value, remove the lead wire to disc motor. � RF signal P-to-P value : 0.46 - 0.66 Vp-p � The repairing grating holder is impossible.

D-E251

D-E200/E201/E206CK

TAP802

� MAIN BOARD � (SIDE B)

S801 (OPEN)

S801

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