Denon UCD-250 - ADJUSTMENT METHOD; Service Program Operation; Adjustment Instruments and Preparation

Ga D-250
CD PLAYER SECTION
The microprocessor contained in this unit incorporates a service program which allows a wide variety of service adjustments to be
ADJUSTMENT METHOD
conducted easily by using the operation buttons.
1. Method of starting the service program
Switch on the AC power while simultaneously pressing the ® PLAY button and the & OPEN/CLOSE button of the CD unit
(UCD-250). When all power has been switched on there will be a transition to the service program. At this time the display section
of the CD unit (UCD-250) display tube will indicate “Q{”.
NOTE: Once the service program starts the operation buttons cannot be used for normal operation.
2. Operation functions when the service program is operating
Operates the focus
tracking servo, slide
and the spindle servo.
il PAUSE
Operation button Operation function Description
OPEN/CLOSE | Opens and closes the disc | @Opening and closing takes place when the rotation of the disc has
holder. stopped.
@ Other operation buttons are performed when the opening and closing
operation is completed.
Wi STOP Stops system operation. @Track number display becomes @/ .
@Press when an adjustment has been completed or is redone.
p> PLAY Operates the focus servo and | @Press at the time of the tracking offset adjustment.
rotates the disc.
Ge.
@ After the operation is completed, the track number display becomes
servo, | ® When the play button has been pressed, the tracking servo and slide
servo, servo are operated.
@ After the operation is completed the track number display becomes
Q3 .
Operation is not normal. @Do not operate buttons other than the above.
@ When a button is operated by mistake, immediately turn the power
switch off.
NOTE: Do not use the remote control while the service program is operating.
3. Adjustment method
(1) Measuring instruments required in the adjustment
@ Dual-trace oscilloscope
OUTLINE DIAGRAM OF ADJUSTMENT LOCATION
1U-2478-1 MAIN UNIT ASS’Y (Component Side)
MAIN UNIT
1U-2478-1
VR60! VR602
VRSOI vRSO2
)
FRONT PANEL SIDE
@ Oscilloscope
64
NOTE: VR601 and VR602 have been adjusted before shipping and do not require adjustment.
(2) Adjustment preparation
Set the adjustment control (VR501, 502) to the} VR501
position illustrated. (T-OFFSET)
VR502
(F-OFFSET)
2. | Adjustment step 1. Tracking offset
2. Focus offset
22