Solved Dell U2414H Monitor won't connect correctly to Win11 Thinkpad T470p

Hi Everyone, I have a Thinkpad T470p running Win11, and a Dell U2414H monitor. The Dell was running smoothly (i.e at native 1920x1080 resolution), until recently. The laptop had to go in for a repair. The main problem was, the built-in screen was malfunctioning, but as it also wasn't updating properly, I asked them to fix that at the same time, and I think they did some kind of 'system refresh'.

Now when I connect the Dell, it defaults to a very low resolution. Right-clicking on the Desktop > Display Settings, shows it registers as a maximum 640x480 (rather than the native 1920x1080).

I've gone onto the Dell U2414H website and downloaded the latest driver. I also installed Dell Display Manager, but that didn't appear to do anything.

When I go into Device Manager, and Desktop > Display Settings, the Dell driver shows up as 'Generic Non-PnP Monitor', which I'm sure is not right.

With both screens connected and on, in System > Display > Detect other display, the Dell does not appear to be registering, as it comes back with 'we didn't find another display' (even though they Identify as 1 and 2).

The version is Win11 Pro 21H2
OS Build 22000.1817
The ThinkPad built-in monitor has a resolution of 2560x1440

Could someone please help my sorry mess

Many thanks, Chigwells

(Edit: thanks to the Mod who moved this to the correct forum)

It's possible one of the laptop's video ports is broken. Both T470p and U2414H each support HDMI and DisplayPort, see if you can borrow a matching cable for the unused video port. Even without a correct driver, most monitors show up as 800x600 or better resolution.

If you don't have a cable, bring the laptop & monitor to a friend's house and try with their PC and monitor.

Thank you @garlin! I normally use the @mini Display Port' to connect them. Following your suggestion I connected with HDMI, and I immediately had the correct 1920x1080 resolution.

I prefer to use the mini Display Port, as it supposedly displays images more accurately. Could you suggest how I can fix this (as I said, before it went in for repair, the mini Display Port connection worked perfectly)?

The replacement motherboard has a bad connector. Your repair shop might not have checked all ports. These ports are soldered on, so it's not like a loose cable. Take it back, and insist they make it work on both outputs.

If it's a defective part, they need to take it up with their spare parts vendor. I wouldn't consider this a complete repair job.

If you can access another DP cable, I'd try that first. (Probably not the issue, though.)

Thanks @garlin and @bobkn.

Just to clarify, I have always used the laptop and external monitor with the mini DP connection and cable, it worked perfectly. It is only since it came back from repair (internal screen wasn't displaying correctly, grey stripes on it, and there was an update issue), that it won't reconnect on mini DP.

This leads me to believe it is some kind of driver issue, especially as in Device Manager the external monitor shows up as 'Generic Non-PnP Monitor'?

With the HDMI cable attached, there is no problem with the monitor, so am I wrong here?

What I will do is connect my Win10 ThinkPad later to check, and I'll update this post

Perhaps there is corruption in the registry. See this...


Basically, you can look here...
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\GraphicsDrivers\Configuration

and see entries related to each of your monitors... including ones in the past...
DELF003YY7707BR0MUL_30_07D7_6A^9A3774EB79DEE3E3E38496CC7DF4D936
QHD32000001_31_07D6_D5^63E1ABDD175E7871DCAEB710418A0F75
SIMULATED_8086_2A42_00000000_00020000_1010100^CDE365D1B3F0942F0CF38BFB8E127A

If you can recognize the problem monitor entry... delete it and restart. It will rebuild the entry and perhaps fix your issue.

Chigwells said:

it won't reconnect on mini DP...before it went in for repair, the mini Display Port connection worked perfectly .....With the HDMI cable attached, there is no problem with the monitor. ..........Dell driver shows up as 'Generic Non-PnP Monitor'

Click to expand...

Monitors will show up using generic driver unless the manufacturer of the monitor provided a driver for it and that driver is installed. Most monitors do show up using generic drivers. Dell does provide a driver for that monitor. As you can see it is dated 2015 so whether it will work in Windows 11, I can not say. This driver does NOT control whether the ports on the monitor work or not.

As @garlin stated, if mini DP worked before you took your laptop in for repair, but doesn't work now, IMO it points to a damaged port or cable. If the repair shop went inside the laptop, that would be suspect. Possibly the port on the monitor was damaged when it was disconnected as well.
If you use a discrete video card, if it was removed during repair, damage to it could have occurred also. Process of elimination is the only way to determine which is the case.

Thank you All, these are really helpful pointers.

I'll try them out and come back. I'm busy for the next couple of days so it will be nearer the weekend.

Greatly appreciated all your helpful insights, TYVM!!!

Update: I have solved the issue, but I don't really understand what happened.

My other laptop is a Win10 ThinkPad T440s, I connected that to the monitor over the minDP cable. Initially it displayed the exact same 640x480 resolution. I went into Device Manager and there were two Display drivers, 'Generic Non-PnP Monitor' and 'Generic PnP Monitor', I uninstalled them both and rebooted. At that point the Dell external monitor displayed correctly (at least, it was still at 640x480, but now the full range of resolutions were available, whereas before this was the max res), I was able to set it to the correct 1920x1080.

When I reconnected to my Win11 T470p, which is my photo editing laptop that I normally use with the Dell, it is working fine again!

There was one other thing I did, I played around with the On-Screen control and changed the input from MiniDP to DP, and back again.

So somewhere in there, it kicked it back into normal service.

So all fixed, many thanks to you all for your very helpful suggestions, greatly appreciated!!!