First post on the forum. One of the family has pressed something by accident on the TV remote (not the Virgin remote) and a 'No signal' message appears. Normally this happens if you press a channel number on the TV remote, however this is usually easily fixed and the Virgin channels recovered by pressing the off/on button on the TV remote.
I've tried various menus on the TV remote to no avail. I looked on one forum and it said the no signal message means the TV isn’t getting any input from the currently selected source, whatever that means... If it refers to the the menu which gives options for TV/HDMI, etc., TV is selected so I'm not sure how I can get the Virgin channels back. The Virgin box appears to be working ok - it seems whatever button has been pressed on the TV remote is causing the issue.
On your remote there will be a button named input or possibly a box with an arrow coming out press that and you should get a screen overlay similar to the picture I have inserted use the up down arrows to scroll to HDMI 1 and press OK, if it's not HDMI 1 it will be HDMI 2 or HDMI 3 etc