Philips EXP212 Service Manual page 16

• To move slide outside hold the "NEXT" button depressed.
• To move slide inside hold the "PREV" button depressed.
• To accelerate the discmotor clockwise hold the "MODE"
button depressed.
• To accelerate the discmotor counter-clockwise hold the
"PROG" button depressed.
• In case the focus is OK the discmotor test can be entered
by pressing the "PLAY" button, to exit the focus test and
return to the main menu press the "STOP" button.
8. DISCMOTOR TEST
Purpose: Check speed regulation of discmotor.
• The speed regulation is switched on and the discmotor
starts rotating. If the speed reaches 75% of the nom.
speed the display shows " D", else "-D".
• In parallel also the state of the focus is monitored
continuously (display " F x " or "-F x ").
• In case the disc speed is OK and the focus is OK the radial
test can be entered by pressing the "PLAY" button, to exit
the discmotor test and return to the main menu press the
"STOP" button.
9. RADIAL TEST
Purpose: Check operation of radial servo loop.
• The radial servo loop is switched on and the set starts
reading data. For CDDA discs only: Mute is released and
an audio signal is audible.
• If the system is on track the display shows " R", else "-R".
• In parallel also the disc speed (display " D" or "-D") and the
state of the focus (display " F x " or "-F x ") are monitored
continuously.
Note for CDDA playback: In case of radial errors the audio
output is muted and muting is not released automatically
when the systems recovers from the error. "-R" remains on
the display. To open mute again press the "NEXT" or
"PREV" button.
• To jump 16 tracks outside press the "NEXT" button.
• To jump 16 tracks inside press the "PREV" button.
• To exit the radial test and return to the main menu press
the "STOP" button, to exit the service test program
disconnect the set from the power source.
Remarks to CDDA playback:
In radial test mode data to the DRAM is written at 1.2 times
the nominal speed, and read from the DRAM at nominal
speed. Because writing is done faster than reading the
DRAM gets full after a certain time.
In normal play mode the system would now wait until the
DRAM is partly emptied again, jump backwards and resume
filling at the last written position. However, in radial test
mode the jumps would disturb measurements on the radial
servo loop.
Therefore this function has been disabled and filling restarts
immediately from the actual position of the pick-up unit. As a
result "jumps" are audible during playback.
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