So basically what my problem is, is that my second monitor has just started displaying no video signal. I have my laptop setup as the primary monitor and have a second one plugged in with an HDMI cable. It was working fine two days ago, but yesterday it started displaying no video signal, I know I am on the correct input and everything is plugged in properly. My laptop detects the monitor and behaves as if the second monitor were displaying something on extend mode. My laptop is a Lenovo Ideapad Y480, running both an Intel HD graphics 400 and a Nvidia Gt 640M LE, it has a 3rd Generation Intel Core i7-3610QM Processor.