Cd Eject Error Detection - Kenwood KDC-MP732 Service Manual

KDC-MP732
Overview
Record the number of times when mechanism error (SW er-
ror) occurred at CD EJECT.
EJECT error recording shall be done in 4 patterns, by the SW
status illustrated below (3 patterns in models other than TYPE-
J).
EJECT error is established when EJECT operation is not com-
pleted after EJECT operation is started before the protect timer
count is completed (False EJECT, or ejection with no CD, is
considered as exception and is not recorded).
(False EJECT is determined when: while chucking is not done,
and when SW status is determined as NO DISC.)
Clearing of record is done in the following situations :
1) After reset is cancelled, when reading EEPROM, the code
is NG.
2) While in test mode, the specified key (Play/Pause key
pressed for 2 seconds) is input.
3) When in EEPROM all-clear initialization mode (refer to
the test mode specification document).
• Indication is shown on the test mode specification docu-
ment.
• Number of times with error(s) is 99 times at MAX.
• Not recorded in test mode [1+3 keys].
• When EJECT was error, re-try 3 times, and count each er-
ror while re-try as 1 error.
22

CD EJECT ERROR DETECTION

Operation
EJECT
q
SW1
(LOS SW)
SW3
(12EJE SW)
SW4
(LOE/LIM SW)
ERR condition
EJECT_ERR1
∗ Trigger for starting the sequence: detecting DISC ejection
by EJECT key. (As an exception, protect EJECT when LOAD
error)
q If the protect timer was counted up before the LOS (SW1)
down edge detection, it is recorded as EJECT_ERR1.
w If the protect timer was counted up after LOS (SW1) down
edge before the 8EJE (SW2) down edge detection, it is
recorded as EJECT_ERR2. [12EJE down edge detection
in models other than TYPE-J]
e If the protect timer was counted up after LOS (SW1) down
edge before the 12EJE (SW3) down edge detection, it is
recorded as EJECT_ERR3. (TYPE-J only)
r If the protect timer was counted up after LOS (SW1)/8EJE
(SW2)/12EJE (SW3) down edge before the down edge
detection of any of these, it is recorded as EJECT_ERR4.
∗ When EJECT is started, if not chucking, it is not counted as
EJECT error (considered as false EJECT). However, EJECT
when SW change is detected.
r
w
EJECT_ERR2
EJECT_ERR4