Sony CNU-500, Installation And Maintenance Manual

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2-5 (E)
CNU-500
AT-100 Main check mode. (AUTO)
EPROM Check
OPTION FLASH Check
OK
RAM Check
OPTION EEPROM Check
SWITCH Check
OK
WRITE
ERASE
READ
S2
S3
OK
AT-100 Main check mode. (AUTO)
EPROM Check
OPTION FLASH Check
OK
RAM Check
OPTION EEPROM Check
SWITCH Check
OK
WRITE
ERASE
READ
S2
AT-100 Main check mode. (AUTO)
EPROM Check
OPTION FLASH Check
OK
RAM Check
OPTION EEPROM Check
SWITCH Check
OK
WRITE
ERASE
READ
S2
2-6-4. Self-Diagnosis Mode
Activate the self-diagnosis mode following the procedure
below.
n
The self-diagnosis mode of CNU-500 is completed when
the system is terminated normally or when an error occurs.
.
Turn on the power switch with the S4 and S5 switches
(on the AT-100 board panel) set to the DOWN and SET
positions, respectively.
a) ROM/RAM Check
. Release the switches when the monitor display shown in
Fig. 1 appears.
Fig. 1
Trouble 1 : Figure 1 is not displayed on the monitor
screen.
Remedy : Confirm if IC45 and its peripheral block
or switches S3, S4, and S5 are not
defective.
Trouble 2 : The RAM check appears as an NG
display.
Remedy : Confirm if IC9 to IC12 are not defective.
b) Switch Check
1. Confirm that Fig. 1 is displayed on the monitor screen,
and set S2-1 to S2-8 sequentially to on (see in Fig. 2).
Next, set S2-8 to S2-1 sequentially to off and confirm
that the monitor display shown in Fig. 3 appears.
Fig. 2
Fig. 3
Trouble 3 : S2 appears as an NG display or appears
as neither an OK nor NG display.
Remedy : Confirm if S2 or its peripheral block is
not defective.
2-6. Self-Diagnosis
S3 S4 S5
UP DOWN SET CANCEL
MODE