A good manual. Had everything i needed to make the repair.
Text excerpt from page 29 (click to view)
3. Mode: Playback
test tape P-4-A100 (10 kHz, â10 dB) L-CH MAIN board CN510 R-CH pin 3 waveform of oscilloscope
CD SECTION [TEST DISC LIST]
pin 1 L R pin 2 V H oscilloscope
Use the following test disc on test mode. â¢ CD: YEDS-18 (PART No. 3-702-101-01) or PATD-012 (PART No. 4-225-203-01) Note: 1. CD Block is basically designed to operate without adjustment. Therefore, check each item in order given. 2. Use YEDS-18 (3-702-101-01) unless otherwise indicated. 3. Use an oscilloscope with more than 10MW 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.
in phase 45Â° good
90Â° 135Â° 180Â° wrong
4. After the adjustments, apply suitable locking compound to the pats adjusted.
BD91 board oscilloscope
Adjustment Location: Playback Head (Deck A). Record/Playback/Erase Head (Deck B).
Procedure : 1. Connect an oscilloscope to TP106 (FE) and TP124 (VC). 2. Turn the power on. 3. Load a disc (YEDS-18) and actuate the focus search. (In consequence of open and close the disc tray, actuate the focus search) 4. Confirm that the oscilloscope waveform (S-curve) is symmetrical between A and B. And confirm peak to peak level within 3 Â± 0.5 Vp-p.
S-curve waveform symmetry
within 3 Â±0.5Vp-p B
Note: â¢ Try to measure several times to make sure than the ratio of A : B or B : A is more than 10 : 7. â¢ Take sweep time as long as possible and light up the brightness to obtain best waveform.