U2414H, laptop HDMI, no signal

I'm having trouble connecting to a Dell U2414H monitor with several laptops. I keep getting no signal. I have other Dell monitors and its just a matter of connecting a HDMI cable to the back of the Dell monitor, select the correct input source on the menu, Windows P on the machine and I would get a display. I have tested the HDMI cable on a laptop and on another Dell monitor and its working fine. Laptop is working fine also. The Dell U2414H works while connected to a desktop with a what looks like a large display port to a pinned connection on the back of the desktop. Do I need a special cable for this monitor to connect it to a laptop? Maybe there is a sequence of events I need to follow. Thanks for your help. I have read some other threads but I'm still wondering.