Latitude 5420 and display resolution when booting from WinPE image (SCCM deployment)

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I've been doing a bit more digging into this and tested the same SCCM WinPE boot image from a USB stick and here it works fine.

However I've also discovered that the problem seems to exist already with the WDS Boot Manager, which must be pre WinPE. Below are 2 pictures of the WDS Boot Manager - one is from the new 5420 model and the other is from a 5490 model and as you can see, the problem is already visible here where the WDS Boot Manager takes up much more screen space on the 5420 model.

WDS boot manager 5420WDS boot manager 5490

Hello,

Could you upload the images to dropbox/google drive and share the link via private message? 

I might be able to do this but since the problem occurs as early as with the WDS boot manager I believe that this is before the WinPE image is loaded and therefore the problem is not related to the WinPE image and missing drivers etc.

When you PXE boot, the network stack switches to a screen where it queries the DHCP server for an IP as well as any ip helper services and then contacts the local WDS server and downloads the WDS boot manager.

Initially the network stack seems to run in FullHD (kind of like a DOS prompt running in FullHD and with a much higher number of character columns and rows than the usual 80x25 from the old days).

It then switches back to the WDS Boot Manager which seems to look a lot more like the traditional 80x25 setup.

Could it be that this switch somehow triggers a different behavior on a 5420 that on the previous models of Latitude computers?

Because this is so early in the boot process that drivers hasn't even begun to load.

I was just replying to another similar thread and saw this one too, so I figured I'd at least link to that other one.

I'm having the same "low res" issue which is hurting our imaging since we use the UDI wizard to customize each image for location, list of software to install, etc. and when those windows are all clipped, they're basically unusable.

Hopefully Dell is working on a fix... for now this was just on a test Latitude 5420 Dell sent us so we could prep for it in our environment, but it'll be a big issue soon when those models start rolling in for production use.

https://www.dell.com/community/Latitude/Latitude-5420-PXE-Windows-PE-video-resolution/m-p/7819978 

Yes I've also found other people having the same problem.

As I wrote, the problem occurs already during the initial WDS Boot Manger initialization so since that's before WinPE loads it must be an issue with either the BIOS or the WDS Boot manager (or a combination of both) as far as I see it.

If I take the exact same WinPE image and put it on a USB stick (using the SCCM Create boot media function) the problem does not occur and since the WDS Boot Manager isn't loaded when you boot from the USB (as far as I know anyway) this also supports my theory.

So far I've been able to instruct those office that have received the new 5420 models to use keyboard shortcuts to navigate the WDI bot that's really not a good solution.

I also discovered that if I attach an HDMI cable directly to the laptop (so when the laptop is not in dock) and then use fn+F8 to flip from internal to external screen and back again while the WinPE image is downloaded, then the resolution seems to be fine when the WinPE image is loaded.

So perhaps it could be related to the way the display is initialized by the WDS Boot Manager?

Our WDS servers are currently running Windows Server 2012 R2 so I don't know if newer versions of Windows Server has a newer WDS version where the problem might have been resolved.

Regards,

Martin Moustgaard

I just got a call from Dell ProSupport that this problem should be fixed in the next BIOS update for the 5420 scheduled to be released in April.

Regards,

Martin Moustgaard

I noticed that 1.4.9 was released from Dell on 3/23.  I attempted to upgrade the Latitude 5420 this morning and this did not fix the problem we are encountering in this thread.  Please advise. 

Thanks!

Matt

I didn't realize they put out an update yesterday. Just saw it now, and the release notes don't mention a fix for the video issue, so they must have already had this one in testing, before they added any patches for this issue?

That probably means we're still looking at the timeline of "end of April" for the fix for this.   That's too bad.

Yep, I'm having the same problem. Originally, I thought the UEFI implementation of the Graphics Output Protocol got fubar'd by Dell, which could still be the issue. What is shocking is that apparently Dell never tested these laptops with WinPE before releasing them.

I think it's okay to say, without breaking the NDA, that the test version we got from  our Dell rep does indeed fix the video issues during UEFI / PXE booting.  We're sticking to the latest production release though, and just having our techs go through our task sequence UDI wizard mostly blind, hitting Alt-F on the last page to finish (since they can't see the buttons).

They did say the official fix would be released towards the end of this month (April 2021) so hopefully we see that soon.  Once they do though, it's still kind of a problem because we'll have to modify our task sequence to update the BIOS first during WinPE, and then boot back into the TS for the rest of the interactive stuff.  Normally we do a BIOS update as the very last step of the process when it's running in the full Windows OS, since that seemed to be the safest option, and we're doing a reboot there anyway, but I guess I'll have to change things up.

Eventually we'll get fixed BIOS versions on the factory delivered machines, but I have a feeling that won't be the case until much later this year once their inventory with old BIOS versions is depleted and they start making new systems with the fixed BIOS and get those into the supply chain.  Even then, you never know if you'll get an old-stock system that still needs the update.

It does - at least on the 5420 I have here in my Lab

It has also listed the following as fixed in the description so I can confirm this:

- Fixed the issue where progress bar is not displayed during the Preboot Execution Environment (PXE) boot.

Regards,

Martin

why is that surprising? lol

why is that shocking? lol