Pioneer CDX-P1250 Servis Kılavuzu - Sayfa 42
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CDX-P1250
7.2.2 TEST MODE
- CD Test Mode
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 tray extraction and return oper-
ations is performed by means of the photo transistor
in this unit. Consequently, if the inside of the unit is
exposed to a strong light source with the outer casing
removed for repairs or adjustment, the following mal-
functions may occur:
*Even with a disc loaded, the unit detects "no disc"
and cannot start play.
*Although a 12-cm disc is loaded, the unit detects
"8cm disc" mistakenly.
When the unit malfunctions this way, either re-posi-
tion the light source, move the unit or cover the photo
transistor.
• During exchanging discs, do not press the keys for
the discs to be exchanged.
42
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.
• If the 8 or 9 key is pressed while focus search is in
progress, immediately turn the power off (otherwise
the actuator may be damaged due to the lens stuck).
• 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.
• During exchanging discs, do not press the keys for
the discs to be exchanged.
Key to adjustment text
inside (12 keys type)
BAND
TRK+/FF
TRK-/REV
7
8
9
10
11
12
DISC-
SOURCE ON/OFF
HEAD UNIT (6 keys type)
BAND
TRK+/FF
TRK-/REV
1
2
3
4
5
6
DISC-
SOURCE ON/OFF