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Question

Laptop screen and TV black when connected via HDMI

by Apr 22, 2015 3:20PM PDT

I have a Lenovo Thinkpad (Edge Series) running Windows 7. It took quite an effort to get it connected successfully to my TV via HDMI (there's a port on the TV and the computer). For quite some time, when I connected the two, both screens went black. I finally stumbled on the solution, which seemed to be dependent on turning on the TV after the connection was made. I was able to duplicate the desktop so both screens displayed.



Following the latest Windows Updates a couple of days ago, I'm back where I started. When I connect the TV, both screens go dark. This makes it impossible to select the Duplicate option in Windows. However, I suspect the computer is connected, as the "No Signal" message on the TV disappears. It seems to me that the problem lies in my laptop screen going dark. But that's just a guess.



The Intel HD4000 Control Panel does not offer multiple displays and never has. I have updated the Lenovo system and the BIOS. My driver for the Intel HD4000 is up to date.



I know connection problems have come up before in other threads. I haven't seen one that deals with the problem I have. The fact that the laptop display goes black when the TV is connected makes it impossible to troubleshoot the connection (though I'm not sure what or how to troubleshoot).



The HDMI cable worked just fine, until a couple of days ago.



Can anyone help? It's a maddening problem.



Thanks!

Discussion is locked

5 Posts
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Answer
So with the tv turned off but...
by Apr 23, 2015 5:07AM PDT

with hdmi cable connected, the laptop shows black? If that's the case, then to me..it says either something not right with the cable or the setup is not compatible with the laptop. Are there other connection you can try?

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Trying another TV
by slideguy07 Apr 23, 2015 6:40AM PDT

I will take it to a neighbour's place and see if that sheds any light. Needless to say, the day before this behaviour began, it worked fine.

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Tried this?
by samkh Apr 24, 2015 2:25AM PDT

Toggle between the internal LCD display and an external CRT display by pressing the Fn and F7 keys simultaneously on the ThinkPad keyboard.
Notes:
The Presentation Director menu window may interfere with the functionality of the Fn and F7 keystroke.
There are generally three display mode settings to toggle through (LCD, CRT, and both).
Some ThinkPad models only support two display modes. CRT only or LCD only.

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F7 didn't work
by slideguy07 Apr 24, 2015 5:24AM PDT

Thanks for the suggestion, samkh. I've tried every combination of Function Keys that there is... there are many threads online suggesting various key combinations using the Alt and CTRL keys as well. But my laptop screen stays dark.

When I remover the HDMI cord after trying F7, I see a message saying it turns on Caret Browsing, and asks if I want to to do that.

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That sounds like IE's F7 message.
by r. proffitt Forum moderator Apr 24, 2015 5:47AM PDT

Try exiting all APPS first.

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