Try the usual. Unplug all connections from the TV, the pull the power, wait 10 minutes and try again. Be aware I take your word you know how to switch from HDMI 1 to 2, etc.
Spent already several hours...and more fighting with the LG csr...I am using several HDMI cables trying to connect an Lenovo B570 running W7ultimate. The TV detects the connection as HDMI PC but while trying to connect the no signal message comes on. Change all resolution possible, 4 cables including gold plated fancy ones...and nothing.
I have another 3 Samsung and one Philips and is just plug and play...
I would appreciate any suggestions...
Thank you in advance,