FH-P404
6.2 CD SECTION
1)PrecautionsY Test mode cancellation
Y This unit uses a single power supply (+5V) for the reg-Switch ACC, back-up OFF.
ulator. The signal reference potential, therefore, is
connected to REFO(approx. 2.5V) instead of GND.Y Disc detection during loading and eject operations is
If REFO and GND are connected to each other by mis-performed by means of a photo transistor in this
take during adjustments, not only will it be impossi-unit.Consequently, if the inside of the unit is exposed
ble to measure the potential correctly, but the servoto a strong light source when the outer casing is
will malfunction and a severe shock will be applied toremoved for repairs or adjustment, the following mal-
the pick-up. To avoid this, take special note of the fol-functions may occur.
lowing.*During PLAY, even if the eject button is pressed,the
Do not connect the negative probe of the measuringdisc will not be ejected and the unit will remain in
equipment to REFO and GND together. It is especiallythe PLAY mode.
important not to connect the channel 1 negative*The unit will not load a disc.
probe of the oscilloscope to REFO with the channel 2When the unit malfunctions this way, either re-posi-
negative probe connected to GND.tion the light source, move the unit or cover the
Since the frame of the measuring instrument is usual-photo transistor.
ly at the same potential as the negative probe, change
the frame of the measuring instrument to floating sta-Y When loading and unloading discs during adjustment
tus.procedures, always wait for the disc to be properly
If by accident REFO comes in contact with GND,clamped or ejected before pressing another key.
immediately switch the regulator or power OFF.Otherwise, there is a risk of the actuator being
destroyed.
Y Always make sure the regulator is OFF when connect-
ing and disconnecting the various filters and wiringY Turn power off when pressing the button ? or the but-
required for measurements.ton ? key for focus search in the test mode. (Or else
lens may stick and the actuator may be damaged.)
Y Before proceeding to further adjustments and mea-
surements after switching regulator ON, let the playerY SINGLE/4TRK/10TRK/32TRK will continue to operate
run for about one minute to allow the circuits to stabi-even after the key is released.Tracking is closed the
lize.moment C-MOVE is released.
Y Since the protective systems in the unit's software areY JUMP MODE resets to SINGLE as soon as power is
rendered inoperative in test mode, be very careful toswitched OFF.
avoid mechanical and /or electrical shocks to the sys-
tem when making adjustment.
Y Test mode starting procedure
Switch ACC, back-up ON while pressing the 4 and 6
keys together.
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ACEC
