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* Adjusting the slice level
Replacement parts requiring readjustment
Mechanical unit (pickup), ICs(IC101,IC201,
IC301,IC251,IC252) in the servo block of
ENS-001 and the peripheral elements
(1) Adjusting method
1.
Connect the analog voltmeter between TP203 (JITOUT) and TP211 (D.GMD).
2. Initialize the DVD player in the following manner:
1) Make sure that no disc is on the tray.
2) While pressing the ON SCREEN and DVD MENU keys simultaneously on the DVD player, turn on
the primary power.
3) Press the POWER key, then "TEST" is displayed on the FL.
(TEST mode can be canceled with the POWER ON/OFF key.)
4) Press the ENTER key to start initialization of EEPROM (takes approx. 3seconds).
5) Press the OPEN/CLOSE key, and the tray comes out.
This key is disabled during the initialization of EEPROM. When this key command is accepted
to open the tray, the initialization of EEPROM has already ended.
3.
With the test disc supplied from JVC (DEMO1004) on the tray, press the OPEN/CLOSE key to let
the tray retreat. (Do not push the tray in.)
4.
Press the ON SCREEN key. The disc rotates for a while and then stops.
5.
Press the PLAY key.
6.
Adjust VR202 such that the voltage of TP203 (JITOUT) indicated on the voltmeter becomes a
minimum.
The absolute voltage of TP203 (JITOUT) changes
with DVD players, so the absolute value cannot be
used to judge DVD players.
In general, the voltage changes from 1.6 to 1.9V
according to the angle of rotation of VR202. (The
minimum value is approx. 1.6V.)
If the changing range or the minimum value
apparently differs from these, the TP203 should
be considered defective.
A sample characteristic variation of TP203
(JITOUT) is shown in the figure at right.
Measuring instrument
The disc supplied with the
player or a disc without flaws on
the market Analog voltmeter
Relation between the angle of
rotation of VR202 and jitter
Angle of rotation of VR202 (deg.)
Measurin
Adjusted
g point
part
TP203
VR202
TP211
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