External monitor not seeing connected laptop

[Muse]

Lenovo P1 1st generation. I have a new HDMI cable connecting the laptop to HDMI3 of my TCL 43S405 43" 4K display. The display is set to read from HDMI3 input. Windows 10 Pro sees the external display. It's set to "Duplicate these displays." But the display does not see a signal. Windows has the refresh rate set at 30 hertz. I tried to change that to 60 hz but Windows said it couldn't, and that I may not have appropriate administrator rights. However, I'm the only account and it's an administrator account. Be that as it may, why doesn't my monitor see the signal? Is it maybe a BIOS setting in the laptop?

 

[Steltek]

Did you try holding down the fn key and pressing F7? If I remember right, this is the key combination you use to manage external displays on that model.

Edit: Yes, it is the right one per the user manual here.

Complete user manual for that model is here.

 

[Muse]

Did you try holding down the fn key and pressing F7? If I remember right, this is the key combination you use to manage external displays on that model.

Edit: Yes, it is the right one per the user manual here.

Complete user manual for that model is here.

Actually it's not fn + F7 key, it's just the F7 key (Windows key + P does the same thing) . If I press fn + F7, I get this dialog:

Pressing F7 turns Caret Browsing on or off. Using this feature places a moveable cursor in web pages, allowing you to select text with the keyboard. Do you want to turn Caret Browsing on?

[Yes] [No]
-------------
However, choosing "Duplicate" does nothing when pressing F7.

 

[Muse]

Windows key + P does the same thing as F7 on the P1. Anyway, nothing happens, display isn't picking up the signal.

 

[ch33zw1z]

Have you tried a different input on the TV? Or a different cable?

Lenovo drivers up to date?

 

[Muse]

Did full update of Lenovo today. Only HDMI3 is open on the monitor, could switch them. New cable, could switch that. I need some sleep now, though... Thanks!

 

[Muse]

Laptop screen's been blanking once in a while for 2-3 seconds. Very annoying. Never used to do that. I have the HDMI cable disconnected too. Dang. Gonna try a reboot.

 

[ch33zw1z]

Laptop screen's been blanking once in a while for 2-3 seconds. Very annoying. Never used to do that. I have the HDMI cable disconnected too. Dang. Gonna try a reboot.

Kinda sounds like a driver issue tho. Driver can get "confused". If you have another hdmi screen to test with it could help also.

Another option is to look at the graphics options themselves for the settings, not just in the windows screen config. I know it sounds crazy, but windows sometimes can't interact with the adapter the same way the adapter software can. Seen it many times before.

 

[Muse]

So... took much needed nap, (I'm 1/2 cup coffee and still a bit groggy), and I figured OK, test those theories... Is the cable OK, is the port on the monitor OK, both of which I'd never used before.

Turns out the cable is bad. Well, I'll test it somewhere else, but a different cable using that same port works, so I gotta think it was the cable. I'm looking at the 43" monitor as I type.

I was already kinda burned out on troubleshooting because my little used fairly new mini-tower rig's SSD seems to have died yesterday, was trying to get the machine to work all day yesterday and couldn't. BIOS sees it but Windows won't boot from it. Install flash of Windows 64bit Pro sees no drives to install to. So, since I have a crutial project to complete by Thursday, am setting this laptop up to sub for it.

Thanks for the help!!!