Pioneer DEH-P47DHUC, Service Manual

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47
DEH-P77DH,P47DH
1) Precautions
• This unit uses a single power supply (+5V) for the reg-
ulator. The signal reference potential, therefore, is
connected to REFO(approx. 2.5V) instead of GND.
If REFO and GND are connected to each other by mis-
take during adjustments, not only will it be impossi-
ble to measure the potential correctly, but the servo
will malfunction and a severe shock will be applied to
the pick-up. To avoid this, take special note of the fol-
lowing.
Do not connect the negative probe of the measuring
equipment to REFO and GND together. It is especially
important not to connect the channel 1 negative
probe of the oscilloscope to REFO with the channel 2
negative probe connected to GND.
Since the frame of the measuring instrument is usual-
ly at the same potential as the negative probe, change
the frame of the measuring instrument to floating sta-
tus.
If by accident REFO comes in contact with GND,
immediately switch the regulator or power OFF.
• Always make sure the regulator is OFF when connect-
ing and disconnecting the various filters and wiring
required for measurements.
• Before proceeding to further adjustments and mea-
surements after switching regulator ON, let the player
run for about one minute to allow the circuits to stabi-
lize.
• Since the protective systems in the unit's software are
rendered inoperative in test mode, be very careful to
avoid mechanical and /or electrical shocks to the sys-
tem when making adjustment.
• Disc detection during loading and eject operations is
performed by means of a photo transistor in this
unit.Consequently, if the inside of the unit is exposed
to a strong light source when the outer casing is
removed for repairs or adjustment, the following mal-
functions may occur.
*During PLAY, even if the eject button is
pressed,the disc will not be ejected and the unit
will remain in the PLAY mode.
*The unit will not load a disc.
When the unit malfunctions this way, either re-posi-
tion the light source, move the unit or cover the photo
transistor.
2) Test Mode
This mode is used for adjusting the CD mechanism
module of the device.
• Test mode starting procedure
Reset while pressing the 4 and 6 keys together.
• Test mode cancellation
Switch ACC, back-up OFF.
• After pressing the EJECT key, do not press any other
key until the disk is completely ejected.
• If the
]
or
[
key is pressed while focus search is in
progress, immediately turn the power off (otherwise
the actuator may be damaged due to adhesion of the
lenses).
• Jump operation of TRs other than 100TR continues
after releasing the key. CRG move and 100TR jump
operations are brought into the “Tracking close” sta-
tus when the key is released.
• Powering Off/On resets the jump mode to “Single TR
(91)”, the RF AMP gain setting to 0 dB, and the auto-
matic adjustment value to the initial value.
6. ADJUSTMENT
6.1 CD ADJUSTMENT