Aref said:
hi oldboy
yes i followed all the steps since after i rescan, all of them apear but when i switch off and then on; all the channels are gone again.
what firmware is?
Aref,
Firmware is the version of software installed on the TV. If you go into the menu of the TV and go to the settings section you should see an option named "about this TV" or similar, on my LG OLED it's right at the bottom but your menu may be different. In there you will see an option to update the firmware/software, the TV needs to be connected to the internet to do this or alternatively you can download it to a USB stick and do it via the USB connection on the TV.
If the TV persists with the issue once it's up to date then I would echo the other members advice and contact LG as it sounds to me like a software issue. As Son_of_SJ suggested it would be helpful if you could provide the model number of the TV if at all possible.