Kenwood DP-1100 B Service Manual page 114

DP-1100B II
3 - 1 - 2 D i s c p r e s e n c e / a b s e n c e detection
W i t h a disc o n t h e tray, w h e n t h e laser b e a m is just f o c u s e d ,
pin DOK of C N 2 b e c o m e s " L " so this d e t e c t i o n c a n be m a d e .
T h e p i c k u p lens is m o v e d f o r w a r d s a n d b a c k w a r d s by signal
FSRCH ( 2 . 5 Hz) t o s e a r c h f o r t h e f o c u s i n g p o i n t . T h u s , w h e n
pin DOK d o e s n o t b e c o m e " L " even after 2 c y c l e s of this
s i g n a l , t h e m i c r o p r o c e s s o r j u d g e s t h a t no disc is present.
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3. OPERATION OF MAIN MICROPROCESSOR
Fig. 3 - 1 B Operation f l o w chart
3 - 1 - 3 D i s c surf a c e / r e a r judgement
Fig. 3 - 1 B s h o w s the o p e r a t i o n f l o w c h a r t . W o r d s at the left of
s o m e steps d e n o t e pin n a m e s of I C 1 5 .