SONY HCD-GNX700
Manual de Servicio

HCD-GNX700/GNX800

2. Turn the adjustment screw and check output peaks. If the peaks do not match for L-CH and R-CH, turn the adjustment screw so that outputs match within 1dB of peak.

CD SECTION
Note:

L-CH peak Output level

within 1dB within 1dB

1. CD Block is basically designed to operate without adjustment. Therefore, check each item in order given. 2. Use YEDS-18 disc (3-702-101-01) unless otherwise indicated. 3. Use an oscilloscope with more than 10M� 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. S-curve Check Connection:

Screw position

R-CH peak L-CH peak R-CH peak

Screw position
CD board JPO102 (FE1) TP117 (VC)

oscilloscope

3. Mode: Playback
test tape P-4-A100 (10 kHz, �10 dB) L-CH MAIN board CN510 set R-CH pin 3 waveform of oscilloscope

+ �

pin 1 L R pin 2

oscilloscope

Procedure: 1. Connect an oscilloscope to test point JPO102 (FE1) and TP 117(VC) on the CD board. 2. Turn the power on. 3. Put the disc (YEDS-18) in and turned power switch on again and actuate the focus search. (actuate the focus search when disc table is moving in and out) 4. Check the oscilloscope waveform (S-curve) is symmetrical between A and B. And confirm peak to peak level within 2.4 ± 1 Vp-p.
S-curve waveform
symmetry

V

H

in phase 45° good

90° 135° 180° wrong

4. After the adjustments, apply suitable locking compound to the pats adjusted. Adjustment Location: Playback Head (Deck A). Record/Playback/Erase Head (Deck B).

A B

within 2.4 ± 1 Vp-p

Note: � � Try to measure several times to make sure than the ratio of A : B or B : A is more than 10 : 7. Take sweep time as long as possible and light up the brightness to obtain best waveform.

Checking Location: CD board (SIDE B) (See page 24.)

azimuth screw

22