The channel map is empty. do you want to start auto tuning?

You must auto tune the TV so it knows which channels it can receive and which it gets no data from. The menu should have this setting. Make sure your cable box or antenna is hooked up to the TV before you begin the auto tune. Also be aware that an antenna will no longer receive analog broadcasts due to the digital switch in 2009.

get the on screen menu up ( press menu on the remote) move around until you find auto tune , move sideways and it starts auto tuning
ti finds all radio and tv stations for you
when finished it may auto save or you will be required to press the ok button then exit

Yes.

You need to do a Full Factory Reset tuning rather than just a rescan.

Rescan simply looks at the place holders where the old channels were stored and refreshes them. A Factory Reset (A.K.A. Shipping Condition) wipes the channel memories and starts again fresh.

Auto tune the channels as found in the manual

1. On your remote, press Menu.
   
2. select Channel and press OK on your remote.
3. select Auto Tuning and press OK on your remote.
4. select Yes and press OK on your remote.

It may have defaulted to the wrong input when it turned back on. If you press the input button a few times it may cycle through to the one that has the channel listing.

Check and make sure you have correct input selected ( ie cable, antenna)
thanks Tom

Hi
Before tuning the set to auto tune mode, make sure the antenna or cable, whatever may, connected to its appropriate sockets at the back of the set firmly. To make it autotune:

As new services are broadcast, it will be necessary to

re-tune the television in order to view them.

Auto Tuning will completely re-tune the television

and can be used to update the channel list. It is

recommended that Auto Tuning is run periodically to
ensure that all new services are added. All current

channels and settings, i.e. locked channels, will be
lost.

[1] Select the SETUP from the main menu by using

Up or Down buttons. Press OK and Setup menu
will be displayed.

[2] Select the Installation from the Setup menu

by using Up or Down buttons. Press OK and
Installation menu will be displayed.

]3] Select Automatic Channel Scan from the Installation

menu by using Up or Down buttons and press OK.

A screen will appear warning that previous digital

programmes and settings will be deleted. Select Yes
and press OK to continue with the Auto tuning.

The television will start to search for all available

stations.You must allow the television to complete

the search. When the search is complete the Auto

tuning screen will display the total number of
services found.

* After search is completed for digital channels, a

message asking whether to search for analogue
channels appears on the screen

** Press the OK button to search for analogue

channels. The following menu appears on the screen
for analogue channel search
OK.

Go to menu.Rescan the channels for cable or free air.

press the preset button on the front panel once then (TV should be on) the on the screen there should be words the likes of (Auto VHF 1 60.00mhz) now the Auto stands for auto tuning VHF stands for its frequency where its going to search the 1 stands for the channel where its going to start with 60.00mghz stands for the lowest signal to which its going to start now that you have understood all that just press the volume up button then it will automaticly locate all your working channels leave till it stops for when does it will start from channel 1 to which I believe that you be able to see the channel working so press the up button on the channel button to check the rest of your channels hope this will solve your problem!

What is the model of the TV please?