Pioneer PD-41 Manuale di servizio - Pagina 27

Sfoglia online o scarica il pdf Manuale di servizio per Lettore CD Pioneer PD-41. Pioneer PD-41 42.
Anche per Pioneer PD-41: Manuale di istruzioni per l'uso (28 pagine)

Stampa la pagina

PD-41,PD-9700

2. Grating adjustment

Symptom when out!

Play does not start, track search is impossible, tracks are skipped.

of adjustment

Measurement instru-| Connect the oscilloscope to TP 1, Pin|

@ Player state

Test mode, focus and spindle servos

mentconnections

| 2 (TRI ERR) via a low pass filter.

closed and tracking servo open.

(See Figure 2)

@ Adjustment location | Pickup grating adjustment slit

[Settings]

50 mV/division

5 ms/division

DC mode

[Procedure]

1. Move the pickup to midway across the disc(R=35 mm) with the TRACK FWD Di or REV EM key.

3. Insert an ordinary screwdriver into the grating adjustment slit and adjust the grating to find the null point. For more

details, see the next page.

4. Ifyou slowly turn the screwdriver clockwise from the null point, the amplitude of the wave gradually increases, then if

you continue turning the screwdriver, the amplitude of the wave becomes smaller again.

Turn the screwdriver clockwise from the null point and set the grating to the first point where the wave amplitude

reaches its maximum.

Reference:

Figure 3 shows the relation between the angle of the tracking beam with the track and the waveform.

Note : The amplitude of the tracking error signal is about 3 Vp-p (when a 39 k? + 0.001 yF low pass filter is used). If

this amplitude is extremely small (2 Vp-p or less), then the objective lens or the pickup malfunction may be

the cause. If the difference between the amplitude of the error signal at the innermost edge and outermost edge

of the disc is more than 10%, the grating is not adjusted to the optimum point, so adjust it again.

5. Return the pickup to more or less midway across the disc with the TRACK REV WW key, press the PAUSE [4] key and

double check that the track number and elapsed time are displayed on the front panel. If they are not displayed at this

time or the elapsed time changes irregularly, double check the null point and adjust the grating again.

Figure 2