07-03-2018 09:38 AM
See this companion thread on Dell's forum detailing my unsucessful attempts to use Dell U2415 monitors with my Thinkpad T450s.
As of now, the moderator of that site has not been able to identify a solution. I have two of the u2415 monitors, and it seems extremely unlikely both pieces of hardware are defective. Therefore, am assuming this is a problem with the Thinkpad. Any ideas what might be going wrong? When I press F7 it gives me the option to select "extend", etc, but nothing appears on the monitor. Similarly, the monitor realizes something is plugged into its DP port (via the mDP port on the Thinkpad), but it is receiving no picture. So it's close to working, but is not working.
Appreciate any help. Anyone else currently using a Thinkpad T450s with a Dell U2415? Barring responses from others with different experiences, I would not recommend buying a Dell U2415 if you hope to connect it to this model of Thinkpad. Though given that the problem appears to be on the Thinkpad's end, I guess I wouldn't recommend buying the Thinkpad if you're averse to these kinds of connectivity issues.
Solved! Go to Solution.
07-05-2018 07:17 AM
Update: am able to connect both monitors to an HP, but only using a DP to DP cable. When I attempt to connect using a mDP (from the computer) to DP (monitor) cable, the HP is unable to connect with either monitor.
The only video outputs on the Thinkpad are mDP and VGA, and the monitors do not have a VGA input. So I think there is either something wrong with the mDP to DP cables, or with the ability of the monitors to take signal from an HP or Lenovo using an mDP cable.
07-05-2018 01:47 PM
Are you using a Lenovo adapter such as this?
I have read about non Lenovo adapters causing problems but I don't remember the specific circumstances (may have been mDP to HDMI)
07-05-2018 04:14 PM - edited 07-05-2018 04:16 PM
I have the same monitor and connects to everything I throw at it. I would be suspicious of the cables, as there are so many specifications that need to be covered by a simple cable.
A good way to tell if it is cable related is to try and see if you get the Lenovo logo at boot, and the Bios to display on the monitor. I would also check using a Live USB linux to see if you've got better luck there.
However, buying a new cable might be a starting point. Try Amazon's basic, they're cheap and work well.
Edit: I have a T460p and I can connect it both via its mDP and HDMI (to HDMI or to DP). I also have another computer connected via DP to DP and a raspberry pi via HDMI to HDMI.
07-06-2018 09:01 AM
This is as close as I can come to your setup: T450s, Dell P2414H, this mini-DP to DP cable:
Works fine duplicated or extended.
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07-06-2018 09:07 AM
Thank you all for the replies, and the example that it works for related hardware. Agreed that Dell's cables are likely the culprit. An Amazon Basic mDP to DP cable will be arriving this weekend, and will hopefully solve the problem. Will post an update either way.
07-09-2018 03:33 PM
As suggested by a couple folks in this thread, the mDP to DP cables that came with the Dell monitors were to blame. Received an Amazon Basics mDP to DP cable today, and the monitors connected immediately. Thanks for everyone's help!