DC10 E, DC20 E
SERVICE HINTS
9
2-3-2 Checking Method
<Hints>
In the DVD, degradation of picture quality normally appears on the screen as block noise, as in the DV. This is because, if an error
occurs exceeding the ability of the error correction circuit, the block by block information of pictures is not played back properly and
thus complemented by the previous picture information. Normally, such block noise appears on the screen when the error rate has
considerably been degraded due to the contaminated disc or flaws, etc. Be sure to check the playback picture quality by the error rate.
<Check Points>
(1) Visual check of reference disc
Check the recording surface of the reference disc for contamination or flaws. If the recording surface is contaminated, softly wipe
the disc outward from its center using soft cloth.
* The reference disc is a DVD-R disc of 8 cm, and classified as NTSC or PAL specification. For NTSC specification,
use DY9-1407-000. The reference disc can be used, not only for checking an error rate, but also for checking the
playback picture on the monitor, because it also contains video images (4:3, 16:9).
* On the unit with different TV system, the reference disc cannot recognize the disc. This means that it cannot be used
for checking an error rate.
(2) Playback error rate check (“SERVICE MODE / ADJUSTMENT”, p.36)
While the reference disc is played back, check error rate in the service mode.
Playback position: Three positions: Inner, center and outer positions. By changing the disc chapter, the playback position can be
changed.(*)
Error rate standard : 3.3 × 10
-3
In the case of NG, execute the steps from 1) shown below.
* Relationships between playback position and chapter
On the reference disc, data is recorded from the inner circumference to the outer circumference.
Example : In the case of a reference disc with scenes 1 to 8
Fig. 6
For NTSC DY9-1407-000 For PAL DY9-1408-000
Playback position Inner circumference Outer circumference
Scene 1 8
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