Perform the following steps to determine the "Check tel line" message
The supplied telephone line cord has not been connected yet
or not connected properly. Check the connections by making sure
the line cord is secure. When you plug the telephone line cord
at the back of the phone make sure you hear it click.
Plug the telephone into a different telephone line
jack inside your house. This is a test to see if it is a
problem with the telephone or a problem with the
telephone jack. If the telephone operates on a
different jack then the problem is with the original telephone
jack.
If the telephone does not work on either telephone jack you
need to determine if it is a problem with the telephone or the
telephone line. If you have a different telephone, plug
that telephone into the telephone line jack and see if you
can hear a dial tone. If there is no dial tone you are
having a telephone line problem, contact your telephone line
service provider.
If you do not have a different telephone to test, take the
telephone to a neighbor or friends house and test, if the
telephone operates on a different telephone line then the
problem is with the telephone line
After testing if you determine it is a telephone line
problem, contact your telephone line service provider.
If you are using this model on a digital phone line
(office, business line) it may not work. This is a
consumer home use telephone that is not compatible to
business telephone systems.
For models with the Link to Cell feature - If you do
not connect the telephone line cord and use only cellular
lines, set the cellular line mode to Cell line only.