Video Section - Sony HCD-GN77D Service Manual

HCD-GN77D
Ver 1.1 2003.08
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VIDEO SECTION

RE-ADJUSTMENT OF THE SERVO CIRUIT
The re-adjustment of the servo circuit is necessary when
the part which relates to the servo circuit is replaced.
Referring to SUPPLEMENT-1 "1. DRIVE AUTO ADJUSTMENT"
(see page 3).
Choose ALL and do the re-adjustment of each item of
DVD-SL, CD and DVD-DL.
THE PART THAT THE RE-ADJUSTMENT OF THE SERVO
CIRCUIT IS NECESSARY.
1. Optical pick-up
2. RF AMP (IC001)
3. DSP IC (IC509)
4. Motor driver IC (IC501)
5. EEPROM (IC204)
Note :
1. VIDEO board is basically designed to operate without adjust-
ment. Therefore, check each item in order given.
2. Use DVD reference disc unless othermise indicated.
[DVD reference disc]
• LUV-P01 (4-999-032-01) (CD)
•TDV-540C (J-2501-235-A) (DVD-DL)
• TDV-520CSO (J-2501-236-A) (DVD-SL)
3. Use an oscilloscope with more than 10MΩ impedance.
4. Clean the object lens by an applicator with neutral detergent
when the signal level is low than specified value with the
following checks.
TE
L 13942296513
Video Level Check (VIDEO BOARD)
Purpose
This adjustment is made to satisfy the NTSC standard, and if not
adjusted correctly, the brightness will be too large or small.
75 Ω
set
J711
VIDEO OUTPUT
Procedure:
1. Connect oscilloscope to VIDEO output.
2. Load a DVD reference disc playback.
3. Check the video signal level is 1.00±0.05Vp-p.
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Oscilloscope
1.00 ± 0.05 Vp-p
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