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A6.2 DVD ADJUSTMENT
If the reference voltage is connected to GND by mis-
1) Precautionstake, turn the regulator OFF immediately, or turn the
This product uses 5V and 3.3V as standard voltages.power OFF.
The electrical potential that is the reference for signals,
Remove the filters and wires used for measurements
is not GND, but VREF (approximately 2.2V) and VHALFonly after the regulator has been turned OFF.
(approximately 1.65V). After the power supply is turned on, regulator ON the
During product adjustments, if the reference voltage isfollowing adjustment and measurement are promptly
mistakenly taken as GND, and a grounding contact is
done.
made, not only would it be impossible to measure the Whenever the product is in the test mode, the software
Baccurate electrical potential, but also the servo motorwill not take any protective action. For this reason,
would malfunction, resulting in the application of a
strong impact on the pick up. The following precaution-special care should be taken to make sure that no
mechanical or electrical shock could be applied to the
ary measures should be strictly adhered to, in order toproduct when taking measurements in the test mode.
avoid such problems. Whenever the EJECT key is pressed to eject the disk,
The reference voltage and GND should not be confused
when using the minus probe of a measurement device.no other keys, other than the EJECT key, should be
pressed until the disk eject action has been complet-
When an oscilloscope is being used special care shoulded.
be taken to make sure that the reference voltage is not Press the EJECT key only after the disk has stopped
connected to the probe of ch1 (on the minus side),
completely.
while the probe of ch2 (on the minus side), is connected If the product hangs up turn the power OFF immedi-
to GND. Further, since the body frame of most mea-ately.
Csurement devices have the same electrical potential as Laser didoes may be damaged, if the volume switch for
the minus side of the probe, the body frame of the mea-
the laser power adjustment of the pick up unit, is turned.
surement device should be set to floating ground.
Attention)
Test mode starting procedure
ACC ON while pressing the ANGLE- and EQ keys together.
Test mode stopping procedure
ACC and Backup OFF.
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E
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130AVH-P6500DVD/UC
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ACEC
