Laptop and projector no signal?

My colleague and I share a projector… With my laptop, he works fine until he goes to my colleague. When she connects the beamer to her laptop the message 'no signal' comes up. If I bring back the projector, the problem also occurs to me. I have already tried with the F-keys, about setting I can't find the projector, double setting I have already, … Brings everything. SOS

Some laptops recognize external monitors and beamer automatically, others you have to manually for a switch or! For this you can use a software (for GrafikKarte), the settings of the operating system (Windows settings, since representation oä), OR (which I find the easiest) the hardware keys (usually F-keys).

You need the button with the icon for external display (monitor icon, like a pillow, with vertical bars left / right) and just the button to trigger the F-keys (CRTL / CTRL / Fn). The biggest trick is not to be too impatient and hectic! Until the monitor / beamer is detected, it can sometimes take 5 seconds or more! And some laptops 'wander' with the corresponding keypress through several different variants! If you are too fast, you miss the right one! Typical are for example: Only FlatScreen, only external, Flat & externally the same (mirroring), Flat & Extern next to each other (extendet Screen).