TV resolution goes down when connected to PC using DP/HDMI connection

I have a Windows 10 Lenovo T440 laptop, which I have connected to a TV using a display Port to HDMI connection.
The TV is a Samsung 55" 1080P LCD TV.

Now, as soon I connect the devices and extend the display from my laptop to the TV, it drops the resolution of the TV to 640 * 400 and does not give me any option to upgrade the resolution. How can I solve this problem?

Lost

Posted 2016-06-05T02:10:08.760

Reputation: 380

Did you disable the built-in monitor from Windows? – Julie Pelletier – 2016-06-05T02:14:39.927

No. Do I need to do that? if yes how? – Lost – 2016-06-05T02:23:11.907

Well I tried TV as the only monitor and that also does not seem to provide more options for resolution – Lost – 2016-06-05T02:54:17.190

Answers

The resolution provided by a graphics adapter is the sum of the total resolution of all the displays used.

You can change those settings by going on the Start button (bottom-left of the screen), Control Panel, Appearance and Personalization, Personalization, and then Display Settings. You then go to the Monitor tab from which you can select the different displays and the resolution to use on them.

Julie Pelletier

Posted 2016-06-05T02:10:08.760

Reputation: 2 065

I tried that. When i tried that on TV, it only shows upto 640 X 480 as only option – Lost – 2016-06-05T02:53:44.363

So you disabled the other display and the maximum output on the TV setting is 640 X 480? – Julie Pelletier – 2016-06-05T04:36:40.847

Are you actually using a direct HDMI cable? Now I'm wondering if you're using some cheap VGA to HDMI adapter. – Julie Pelletier – 2016-06-05T04:38:11.430

I am using Thunderbolt to HDMI adapter. No VGA involved – Lost – 2016-06-05T16:47:06.067

What's the model? I'm very curious, especially considering I thought this was only for Macs. – Julie Pelletier – 2016-06-06T04:20:09.767

Its Lenovo T440 – Lost – 2016-06-06T21:45:56.977

That is already in your question. I meant what's the model of your Thunderbolt adapter? – Julie Pelletier – 2016-06-07T03:43:25.147

~~You won't get much more more than 640 x 480 with VGA output.~~

https://en.wikipedia.org/wiki/Graphics_display_resolution#VGA_or_SD_.28640x480.29

Check if your PC Video Output looks like this : https://en.wikipedia.org/wiki/VGA_connector

Did you try updating your video drivers ?

http://support.lenovo.com/fr/fr/products/laptops-and-netbooks/thinkpad-t-series-laptops/thinkpad-t440/downloads/DS103422

Mantisse

Posted 2016-06-05T02:10:08.760

Reputation: 53

You may be confusing the name used for a specific display resolution with the capabilities of the graphics card. A very common resolution limit for VGA output is 2048x1536. – fixer1234 – 2016-06-05T06:38:15.437

Right, VGA connector but resolutions like QXGA. Checked on http://www.fourmilab.ch/documents/howmanydots/ What would you say the SD resolution comes from then ?

– Mantisse – 2016-06-05T06:46:24.297

Names have been assigned to certain common display resolutions based on their "multiple" of the original VGA resolution. However, that's unrelated to what the graphics card can output through the VGA connector. The quality of the Digital/Analog Converter on the graphics card determines how high a resolution can be outputted with good quality. Even on inexpensive cards, the manufacturers typically rate them as capable of up to 2048x1536 without noticeable degradation. The 640x480 doesn't really come into play as any kind of limit on VGA output. – fixer1234 – 2016-06-05T07:04:10.987

Ok, I did not know all that about what is still said to be VGA. – Mantisse – 2016-06-05T07:16:00.890

Actually it is MDP(Mini Dislplay Port) not VGA – Lost – 2016-06-05T16:46:25.850

@CoffeeBean See edit for hint. – Mantisse – 2016-06-05T19:04:09.127

@CoffeeBean Did you try on another computer screen / TV screen ? – Mantisse – 2016-06-08T19:58:15.253