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In Service mode, the CPU checks for circuit integrity and
displays the test results on the LCD. Use this mode for
quick fault isolation.
How To Enter Service Mode
. Set to "Factory mode".
. With the LCD shown "FACTORY 024D", press the
"TEXT" button, and "SERVICE MODE" will appear on
the LCD.
LCD
—
LISERVICEL|MODEL]
Note: Pressing the "TEXT" button again, returns the mode
to the FACTORY MODE.
No
—
(All LCD's light up.)
ae
+ Digital Error Rate Display
0
ch
+
0
O~f&
O~m
Ot-
Qtr
123
+++
000
i Indicates main data error.
Indicates AUX data error.
Indicates SYS INFO data
indicates CORRECTION FAIL data
Indicates UNRELIABLE data
* Meaning of data error codes
0-000-00000000
EX:
0-000-00101000
OK
0-001-00000000
COUNTER
*L— (AUX data error)
button
Test item
LCD message
Remarks
0-010-00000000
operation
a
count
(SYS INFO data erior)
a
(LCD) test
0-000-01101000
NG
1-1711-11111111
9-~999-99999999
SFC communica-
tion test
DAIO communica-
tion test
Total error rate
SFC OK or SFC NG
DAIO OK or DAIO NG
Displays number of
errors generated in 32
segments (for 1.3 sec.)
in hexa decimal.
L3 BUS communi-
|L3 BUS OK or
cation test
L3 BUS NG
Soe camimntc
3
DRP communica. |DRP OK or DRPNG | [cation Test
A-AAA~AAAAAAAA
:
pages
tion test
25~27.
F-FFRF-FFFFFFFF
ee
|
Main data error
See Digital
Error Rate
Display.
* If the data error code is "NG'", check test
Step 4. ~Bon
page 33.
@ LSI, DRP SFC and DAIO Communication
Test
The CPU is connected to its peripheral ICs (DRP, SFC
and DAIO) via a parallel bus consisting of clock, data,
and control lines. If an "NG" message is displayed on
the LCD as a result of self diagnostics in Service mode,
25
itis necessary to determines which IC out ¢ DRP, SFC
and DAIO (including their peripheral compmenis) is
defective. The flowcharts on the following pages provide a
quick troubleshooting guide to locate the de'eective 1C(s).
PCS 79 285
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