©1998 by TELES AG Berlin, Version 1.1/fon-eu/15.07. Page 47
Solving Minor Problems on your Own
Not every error on your telephone means that it defective.
Your ISDN line was attached to the household power net by the tele-
phone company. In case of a power outage the telephone cannot oper-
ate.
Faults and troubleshooting
Problem
Possible causes
Solutions
Receiver lifted, but no
dial tone
Device not attached
Power outage
Both B channels occupied by
other terminal devices or
parked calls.
Check plug at the wall
socket and on the tele-
phone.
Regain power or set
emergency power switch
to “on”.
Wait till a B channel is
free.
No display
Plug of the telephone cable
not properly attached
Power outage
Incoming calls without call
numbers transmission and
ring tone too quiet.
Check plug at the wall
socket and on the tele-
phone.
Regain power or set
emergency power switch
to “on”.
Increase ring tone vol-
ume.
No dialing possible
Telephone blocked
Remove telephone blocks