'
'
5-2. Description of CD Interface
Signals
Name 1/0 : Function !
1c
No_
/Pin
. I
No.
0 IError flag. Outputs
"H"
when I
C2PO !data correction is disabled. IC40l @
BCLK 0 IBit clock. IIC40l @
SDATA 0 ISerial data output. IIC401 @
LRCK 0 UR-channel identification clock. IC401 @
16MHz 0 i!6.9344MHz output. IC401 @
WFCK 0 IFrame clock. IC401
@)
EXCK I Sub-code read clock. IC401 @
SBSO 0 ISub-code data. IC401 @
SCOR 0 ISub-code sync. IC401 @
L-
MUTE
0 IOutputs
"L"
when playing back IC404 @
(DM) music and
"H"
in other modes.
!RO
0 Interrupt request. IC404 @
COCK 0
CD
mechanism control commu- IC404 @
nications clock.
HOCK I Host communications clock. IC404 @
DBO
1/0 Data bus 0. IC404 @
DB l 1/0 Data bus I. IC404 @
DB2
1/0 Data bus 2. IC404 @
DB3
1/0 Data bus
3.
IC404 @
RESET I Resets the
CD
hardware. IC404 @
5-3. CD Interface Connection
Reference Diagram
C2PO
LRCK
DATA 6CLK Serial data
PROCESS communications
DATA
IC401 16MHz
CXD1167 WFCK
EXCK Sub-code
S6SO
communications
SCOR
~1r
L-MUTE
(OM)
Audio control signal
MECHANISM IRQ
CONTROL UP
06US
(4bit)
063
IC404
062
UPD75006
061
Hostcommunications
060
CDKC
HOCK
RESET
6.
CD
DRIVE
UNIT
REPLACEMENT
PROCEDURE
Remove the GENESIS II/MEGA DRIVE
II
from
the SEGA CD II/MEGA CD
II
and unpl
ug
t
he
power cord
of
the SEGA CD II/MEGA
CD
II
from
the AC outlet.
Replace the CD drive
un
i
t.
Connect the power adapter and
GE
NESIS
II/MEGA DRIVE II.
Tum
on the door close detection switch (SW401)
forcibly to turn the power switch on. Check that
the laser emits a beam for about 2 seconds and the
pickup's object lens moves up and down.
Caution: Be careful; it is dangerous to look
straight at a laser beam.
Do not bring your eyes too close
to
it.
Adjust the
EF
balance. (VR40I)
Adjust the tracking gain. (VR402)
Check that an
RF
wavefonn
of
approx. l.5Vp-p
can be observed
at
IC402-2 (TP-RF).
Replacement complete.
9
