I have an inspiron 15 gaming series laptop with Windows 10 and a Sony DLP TV. Yesterday I used my PS4's HDMI cable to plug my laptop into the TV and it worked instantly. Today, I tried doing the exact same thing and the TV says no signal. I've tried multiple HDMI cables, I've tried changing the HDMI in port on the TV. I've tried using the projector settings. I've tried shutting the computer down and plugging the HDMI cable before turning on the laptop. Nothing has worked. Please help.
Your laptop might be outputting a higher resolution than the TV can display. You mentioned it was a DLP TV so its probably only 720p, so if you laptop is outputting 1080p it might not work.
When you have the laptop connected and the TV set on the proper input, do you even see the TV being detected by Windows under Display Settings?
It does recognize that there is a separate monitor present in the display settings.
I tried different resolutions (I went down to 900p). But I figured it wasn't the problem because it worked yesterday by just plugging it in (I didn't change the resolution when I plugged it in yesterday and it worked fine on my tv).