Screen malfunction after laptop panel replacement

[dvilla]

I have a ThinkPad E15 Gen 4 (model: 21E7S1A100)

I wanted to upgrade the image quality of the screen so I replace it for a better panel, a N156HCG-GQ1 from Innolux

I installed it, and at first, during boot and bios screens, it seemed to work great!

However, after booting into Windows, everything fell apart. The screen was full of artifacts, incredibly laggy, and essentially unusable. The brightness keys worked fine, but everything else was a mess.

Here’s what I’ve tested so far:

• Linux: The panel works perfectly, no issues whatsoever.

• Windows:

  • Works fine in Safe Mode.

  • Works fine if I disable the Intel graphics drivers and use the windows basic display adapter

  • Works fine if I disable the Intel Internal GPU and only use the Nvidia GPU inside the laptop.

  • I tried installing the oldest and latest available for Intel GPU, one from 2022 up to the latest one in the Intel webpage, also the officialy supported lenovo drivers

Is this a Intel Xe Iris issue driver issue? the EDID of the panel shows up correctly on windows, all the screen data and refresh rates presets are present and correct

I suspect this is lack of support for this screen in the Intel Driver since this panel was disontinued before this CPU was launched and no modern laptop was going to came with this CPU/Panel configuration

Thanks in advance!

[Mike_Intel]

Hello dvilla,

Thank you for posting in Intel community Forum.

For me to further check this, please help provide the following details:

1. Just to check, is it working fine in Windows before the panel replacement?
2. What is the model of your processor?
3. What is the model of the Graphics controller?
4. Have you also trued contacting Lenovo about this issue since everything is controlled by their BIOS?
5. What is the Graphics driver version installed?
6. What are the troubleshooting steps that you tried so far?

If you have questions, please let us know. Thank you.

Best regards,

Michael L.

Intel Customer Support Technician

[dvilla]

1. Yes without issues

2. Intel i7-1255U

3. Intel Iris Xe Graphics G7 96EUs and NVIDIA GeForce MX550

4. I haven't contacted lenovo

5. I tried about 15 different versions, from the oldest to the newest avialable

6.

I tried reinstalling Windows with a full disk wipe

I tried Windows 10 and 11

I tried reseeding eDP the connection

I disabled all hardware and security checks in the bios

I installed the latest bios

I tried a bunch of EDID overrides using CRU (panel name, resolution, refresh rates, etc)

[Mike_Intel]

Hello dvilla,

Thank you for the update.

Let me ask additional information about this issue:

1. You mentioned that you have 2 Graphics controller. Which one your your Main Graphics?
2. Have you also tried checking this issue with NVIDIA since it is possible that your main Graphics is this one?

Base on the information that you shared so far, this issue is a possible compatibility issue.

If you have questions, please let us know. Thank you.

Best regards,

Michael L.

Intel Customer Support Technician

[dvilla]

Yes, the main graphics is the iGPU (the Intel one)

If I go to the device manager and disable the iGPU and only use the nvidia GPU the screen works fine (except for brighness control)

If I go to the device manager and do the inverse, the screen glitches

If I go to the device manager and disable the Intel driver and use the Windows Generic Driver the screen works fine also

thank you for your help

[Mike_Intel]

Hello dvilla,

I hope this message finds you well. 

Were you able to check the previous post?

Please let us know if you still need assistance.

Best regards,

Michael L.

Intel Customer Support Technician

[Mike_Intel]

Hello dvilla,

Thank you for the update.

Since it was working fine before and the change in hardware started the issue, it would be best if you contact the OEM manufacturer which is Lenovo for further checking of the compatibility and configuration.

If you have questions, please let us know. Thank you.

Best regards,

Michael L.

Intel Customer Support Technician

[Mike_Intel]

Hello dvilla,

I hope this message finds you well. 

Were you able to check the previous post?

Please let us know if you still need assistance.

Best regards,

Michael L.

Intel Customer Support Technician

[dvilla]

finally I ended up buying another panel, an LG LP156WFE-SPD4 which worked flawlessly, seems like it was just a faulty panel

[Mike_Intel]

Hello dvilla,

Thank you for the update and I am glad that the issue is now fixed and there is no problem with the Graphics.

However, if you still have clarifications, you may still check this with the system manufacturer.

Since the issue is now fixed, I need to close this inquiry. 

If you need further assistance, please post a new question as this thread will no longer be monitored. 

Thank you and have a great day. 

Best regards,

Michael L.

Intel Customer Support Technician