SONY HCD-GB3
Service Manual

HCD-GB3

Adjustment Location: Record/Playback/Erase Head

CD SECTION
Note: 1. CD Block is basically constructed to operate without adjustment. 2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated. 3. Use an oscilloscope with more than 10 M� 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. 5. Check the focus bias check when optical pick-up block is replaced.

FOCUS BIAS CHECK
oscilloscope (DC range) BD83S board TP (RFACI) TP (VC)
+ �

Procedure : 1. Connect oscilloscope to TP (RFACI) and TP (VC) on the BD83S board. 2. Press the I/1 button to turn the power ON, and press the Z (CD) button to open the CD disc tray. 3. Set disc (YEDS-18) on the tray and press the CD 7 button to playback. 4. Confirm that oscilloscope waveform is as shown in the figure below. (eye pattern) A good eye pattern means that the diamond shape (�) in the center of the waveform can be clearly distinguished.
VOLT/DIV: 200 mV TIME/DIV: 500 ns

level: 0.9 ± 0.4 Vp-p

Checking Location: � BD83S Board (SIDE B) �

TP (VC)

IC201

TP (RFACI)

17