ND-71762 (E) CHAPTER 8
Page 93
Issue 2
MAINTENANCE PROCEDURE
(5) Diagnostic Work
START
END
When system message 13-B is displayed, Turn ON the MBR Key on the CCH/CCT circuit card,
and then set the MB key ONOFF.
System message 13-B is displayed FAULT : CCH/CCT circuit card is faulty.

System message 13-B is not SUPERVISION FAULT
displayed
Paragraphs 3.3 or 3.4