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PR-8210-A
Problem
Cause
Check Point
| |
Disc fails to rotate when PLAY
button is pressed.
Laser beam not on.
No lens up operation
Defective focus motor
Defective bridge balance
| adjustment
No FOCS ON
signal
Defective drive circuit
| Proper focus cannot be
attained
Lens needs cleaning.
Defective RFAM
Slider beam axis out of
alignment
Excessive TANG or TRKG
bias
Defective FOCS gain
adjustment
Defective FOCS servo circuit
| tivity.
| Check whether LÁSER ON switch is applied to LSPS
VSOP adjustment, step 3.
| shape curve at VSOP TP-1 when lens is moved up.
Check whether inter-lock switch or lid switch has
depressed when the lid is closed.
Check inter-lock switch and lid switch for conduc-
(12) from CONT.
Check relevant LSPS points, especially if the +12V
line tends to be low.
Measure DC resistance in focus motor. Normal value
is about 1052.
Check that there is no obstructuion to focus motor
movement.
Check presence of FOCS ON signal at VSOP (М7-5)
when PLAY button is pressed.
Check for generation of drive voltage at VSOP (N5-5).
Clean lens.
Check that the focus error voltage describes an S-
Normal level: +2V р-р min.
Place a piece of paper over the lens, and move
the lens up. If a "bight" is taken out of the beam
spot, the problem is due either to misalignment of
the slider beam axis, or excessive bias.
TANG bias at ТР-12: 0 :20mV
ТАКС bias at TP-7: 0 520тУ.
VSOP adjustment, step 11.
Check Z1, Z3, 01 and other elements.
ee
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