ThinkPad P50 Screen Upgrade (30 pins eDP → 40 pins)

Hello,

I own a Lenovo ThinkPad P50 and I would like to upgrade the stock panel, which is an InnoLux N156HCE-EEA.

This panel is a 1080p / 60Hz / 300 nits / IPS / 800:1 / 71% NTSC that uses a 30 pins eDP connector.

My goal is to have a display with higher refresh rate, higher brightness, higher contrast ratio, lower response time, and better colour fidelity.

Also, I am not willing to downgrade to a TN panel, I want to stick with IPS.

So I have looked at displays on panelook.com, and I found many displays meeting these criterias :

• BOE NV156FHM-N4J - https://www.panelook.com/NV156FHM-N4J_BOE_15.6_LCM_overview_41414.html
• AUO B156HAN10.0 - https://www.panelook.com/B156HAN10.0_AUO_15.6_LCM_overview_40445.html

Any of these would be perfect, but there are 2 problems :

1. These panels use a 40 pins eDP interface, but my current cable outputs to 30 pins.
2. These panels don't use the same fixation locking system as the ThinkPad P50's : the stock panel is screwed in place with 4 screws in the corners, those 2 panels don't have the mounting holes.

To address the first problem, I have already ordered a 40 pins ⟷ 40 pins eDP cable on AliExpress (here is the link : https://www.aliexpress.com/item/33003121092.html?spm=a2g0s.9042311.0.0.61476c37FkObYq)

But about the fixation locking system, I am clueless how to install a panel like this in my machine.

Has anyone ever dealed with something like this ? If yes, how did you attach the panel to the frame ?

Thanks in advance !

 

For mounting get some double sided rape / foam.

Mine doesn't use mounting tabs / screws but 1-3mm DS tape to hole the panel to the lid but, the bezel makes sure it's secure as well.

 

Oh, so I guess most of the new laptop panels are just taped instead of screwed ?

Also i'm sorry, what do you mean by foam ?

Thanks !

 

Foam with tape on each side to keep things from moving around/clanking.

 

Did Lenovo really made these laptop with a 30pins edp display ? what a shame, 40pins edp display weren't that more expensive. My main concern would be to know if all 4 edp lane are present and working, it might not be the case..

 

The 1080p version comes with a 30 pins eDP whereas the 4K has 40 pins afaik

 

Yes but did the motherboard still the same on 1080p and 4k variant ?

 

In my case it was a cable / panel swap to 4K from FHD.

MOBO doesn't need any changes to make it work.

 

Do 4K panels require 4 lanes?

 

Not necessarily. It depends more on the GPU and how many lanes are provided there. More lanes means you can extend it to more panels / displays.

https://en.wikipedia.org/wiki/DisplayPort

It gets kind of nerdy but, more lanes = more bandwidth / more bandwidth = more resolution / more displays / higher refresh rate

However more isn't always better. 1080/300hz is a bit too smooth. Finding 4K/120hz can be a hassle. There's a happy medium with each level of Res vs RR.

 

I see i see but I am not looking for 4K anyway.

If I understood correctly you have successfully done the swap before, so you went from a 2 lanes panel to a 4 lanes, correct ?

On this page i compare the 4K version and the 1080p : https://www.notebookcheck.net/index.php?id=127065&specs[]=30386&specs[]=32503

Apparently, the two models have the same mainboard so I should be fine using 4 lanes panels right ?

Also, how does your BIOS behave with the new panel ? I have had some issues with other panels in the past where the panel couldn't display anything else than Windows, but those were 30 pins 120Hz.

Thanks for the answers !

 

4 lanes is dependent on your GPU.

4 is better than 2 in respect to being able to choose more options.

Some BIOS' have whitelisting of particular panels that will be allowed to be swapped into the chassis. My BIOS doesn't have this issue.

30/40/50 pins doesn't make the difference in it working or not it's whether the OEM allows the panel to be used and/or whether the electrical signals have enough power being provided through the cable. If you're capped at say 5V and put in a panel that need 7V it won't work. If you supply 10W "V*A" and the panel has a max of 20W at peak performance you'll be limited in what it will display / refresh at.

There's a lot of factors in making things work that are device specific. There's no real across the board answer, though standards in place mitigate some of this it's still not a 100%.

 

4k require 4 lanes, otherwise you wouldn't be able to drive all of those pixel due to bandwidth limit. Although it could works, there is only a few HBR3 4k display out there

 

It all ties together based on the HW being used. If you have a GPU with 2 lanes but, can hit the bandwidth requirements you can drive a 4K panel. The experience might not be the best but, you can do it. eDP lanes / bandwidth hasn't kept up with the speeds needed...errr MFG's haven't kept up with implementing it based on price / availability of the newer spec's. There's usually some delay in designing new HW for new Spec's of a year or two before they hit the market. So, while you might buy a laptop or GPU in 2021 it might still be using a spec like DP1.4x released 5-6 years ago if eDP 2.0 hasn't been manufactured / released into the wild yet.

4K panels being used in the traditional sense like TV's have more room to install components that meet current spec's. However based on the quality of the picture / market pricing typically aim for 120hz or 60hz due to content being produced only hitting those RR's. With 8K it's mostly the raw content for the granularity being recorded and then down sampled into 4K once edited or displayed in 8K potentially in a theater environment with the screen real estate to provide a crisp image on play back.

https://www.notebookcheck.net/GeFor...-RTX-3060-Laptop-GPU_9828_10478.247598.0.html


As you can see even the most recent cards being discussed around here and elsewhere are still using the 1.4 spec as I mentioned above.

 

Hello guys,

So few days ago I received my 40 pins cable, and I'm now looking at the said panels.

I am still unsure if this is gonna be compatible or not... what exactly should I be looking at ?

@Tech Junky was talking about graphics cards having to support 4 lanes, but I happen to have integrated graphics + discrete GPU (the NVIDIA Quadro M2000M)

How could I know if they actually do support 4 lanes ? Also you were talking about voltage, how do I know if the motherboard delivers enough voltage ?

Thanks !

 

Ok... for instance I'm running UHD630 / GTX1650 and a 4K panel.

If you take your existing panel and compare it to the new panel on panelook.com things should be comparable in spec's. The most obvious should be that the size matches up within a couple of mm's. The next thing to look at is the mounting. Power is another consideration to look at to make sure there's not a significant difference.

While this card will run up to 4K even FHD shows potential performance issues depending on use.

https://technical.city/en/video/GeForce-GTX-1650-mobile-vs-Quadro-M2000M

Based on this (below) and reviews.... performance will depend on what you're using it for. The biggest restriction is the GPU which can be upgraded if you're gaming or doing something that's more intensive than surfing / etc.

 

I am not so worried anymore about the mounting process of the panel, and the panel should be the same size... right ?

I mean, I am looking at 15,6" panels so it should be fine I guess.

What actually worries me are potential hardware compatibility issues, the following picture compares the panel I have (on the left) and the panel I want (on the right) :



As you can see, there is a an 7W difference in power consumption, so my question is : is it gonna work or just drain more power ?

Also I am not planning to play games on this computer, I am just trying to get the maximum comfort with this panel (500 nits, 100% sRGB, 1000:1, 144Hz)

 

Well, you'll draw 3.5X the power which really only makes a difference when unplugged.


Physically you're off on the sizing by almost 10mm which is significant/


You're going to need some double sided tape to secure the panel tot the lid since there's no bracket on the new model.

144hz isn't really necessary if you're not gaming. It simply adds to the cost / power draw. My 4K is 60hz and it's fine for daily consumption but miles ahead of the panel it replaced due to the polarization being off by 45-90 degrees causing vision issues.

https://www.panelook.com/sizmodlist...signal_type_category=70&st=E20&by=desc&page=6

Based on what you're looking for being FHD / 60HZ+ here's a list including your original / selected and the fitting options either 120/144hz
The brightness isn't 500 but, 300 which is good enough for indoors. I have 500 on mine but keep it turned down to ~40% brightness or less most of the time unless sun hitting the panel makes it hard to see.
The big jump is going from 262K colors to 16.7M colors which will improve the visual experience.
The matching of size = mounting in place already for a faster swap out.
Also, going from 6-bit to 8-bit will make a difference as well.
Not to mention the almost doubling of color saturation NTSC RGB / Adobe will make it feel better.

https://www.panelook.com/modelcompare.php?ids=28558,40445,32204,33006,34302,35106


To make it easy the B156HAN04 (120hz) would be a direct swap while the B156HAN07 (144hz) would require the cable swap.

The other thing that comes to mind is whether or not the M200M will get enough power to drive 144hz over 120hz. Being a bit on the safe side I would opt for the 120hz options as to not push things too much unless you're open to upgrading the MXM to a newer / more powerful option.

 

Thanks for the explanations !

Looking at the B156HAN10.0's power consumption and physical incompatibility, i'll just pass on this one.

About the B156HAN04.2 and B156HAN04.5, i'm afraid of the reponse time being 25ms, which is pretty high for 120Hz panels imo...

I have actually looked for 120 Hz panels but every time there was a downside somewhere, like the response time being too high, the brightness being too low... The 40 pins panels just looked so much better.

About me looking for high refresh rates, that's because I am used to them, I own two 165Hz monitors for my desktop computer and it's hard to go back to 60Hz... it just feels slower and not so responsive. I like having smoothness even when moving my cursor or dragging windows, etc...

And I guess you are right, 300 nits should be enough as long as the panel is IPS, has better colours and high refresh rate.

The B156HAN07 & .1 sound like great options, I've messaged some sellers on eBay to know if they actually ship this one and not "compatible" panels like they love to do.

Also, I'd have one last question...

I actually have bought a B156HAN04.5 in the past, but they shipped me an N156HHE-GA1 instead which is a TN panel but also 120 Hz.

After noticing it wasn't the correct model, I immediatly sent it back, and ordered the same model on another more "trusted" website.

Guess what ? They sent me the same panel, then I noticed most sellers like to send N156HHE-GA1's instead of B156HAN04.5.

Anyway, the first panel I received was working fine, I really disliked the TN view angles but technically it was doing it's job.

The second panel though, was working on Windows, but not in UEFI or anything else... I couldn't see the booting splash screen, or the boot menu, nothing...

So I also sent that one back. Now I'm wondering the potential causes of this, and if this could happen with the B156HAN07.1... ?

Any ideas ?

Thanks again for the clear responses

 

I had the same issue with comp panels and went through kreplacement.com after pestering them to confirm actual models being sent / the edp cable I needed as well to make it a smooth transition.

I didn't really want to deal with CN / shipping but, all o the other sellers wanted to confirm compatibility before shipping which of course was an issue as this model never had a 4K option.

As to the splash/bios that's natively going to be picked up by the CPU iGPU not the dGPU depending on how things are setup, display issues on power on / POST might be an issue.

Before swapping things around I would change it from a fast boot to a different option to see if it persists. My laptop just gives some stupid splash screen w/o indicators how to enter it but, not an issue to figure out w/ 3 F keys being the option to enter the screen or DEL.

What I posted above for options is on the safe side of things. If you want to take a chance on +/- a couple mm's for something offering lower response times. The 4K I went with has higher response times but, I don't really notice it. I did notice it when using a DX12 option of a program the other day vs the normal .exe I use and could see it tiling when switching screens. I go into graphics settings and manually set programs to use the dGPU for better rendering / response as some things perform better. The trade off though is CPU going up as it thinks it needs to make a copy before passing it to the dGPU *shrug* It's just a battle to deal with either way sometimes until a patch gets rolled out for something.

I ended up going with a NE156QUM-N66 after finding I couldn't find anyone w/ a B156ZAN05.x in stock anywhere reliable. The only real difference was 60/120hz, the other specs were pretty much the same in the end.

 

From what I see, most sellers on eBay don't really care what device I use, they just ship the panel without asking questions. Just gotta make sure they ship the correct one before ordering I guess.

Isn't the integrated GPU active on windows under light load ? From what I understood the dGPU only gets to work when intensive calculations have to be made, else it would be a huge power waste.

I have tried to disable fast boot when I had that issue, it didn't change anything.

I first thought about the panel's EDID profiles not containing an 1920x1080@60Hz profile (the supposed POST/UEFI configurations), but I didn't investigate any longer as the panel had to be sent back.

I was also told that my laptop's motherboard didn't "whitelist" that particular version of the panel ? (the one that worked was Rev. C1 and the one that didn't was Rev. C2) but I personally think this is BS.

About the panels above, I think that I rather trade 200 nits (that are as you said potentially useless) with a panel that drains less power and has the correct mounting system.

Because that's really what it is, I don't see any major difference between the B156HAN10.0 and the B156HAN07.1 except what I said.

My current panel has 220 nits and I'm okay with it, so 300 should do the trick.

Anyway, I will order the B156HAN07.1, mount it and report back here, maybe all this knowledge is gonna help out somebody out here who knows

Thanks for the help !

 

iGPU is always active if you don't tell windows to use the other for particular programs. If you specify programs in "graphics settings" it will be forced to use it. The only thing about it is the iGPU is still in use copying info to the dGPU.

iGPU is what's used at boot unless you specify in the bios if there's more than one i.e. iGPU & dGPU - I see this being the case on my server when I added dual GPUs for mining w/ dedicated display ports to plug into. Laptop's are a bit different in how they're coded to process boot up displays. There are always exceptions though depending on the MFG implementation as some laptops disable the iGPU completely in favor of the dGPU.

EDID is what a whitelisting is looking for but, a REV difference shouldn't impact this process but, could. I think it's just a PITA put in place by OEM's to control the options you can use. It's just a hurdle that can be overcome when there's a will there's a way to circumvent this.

Though the only EDID use I can think of is when there was a chance between LVDS / eDP being used in the same system when they were battling things out for which was being implemented. There were systems at some point using both interfaces as an option. Since eDP is more dominant now I think the hardcoding of EDID lists has subsided substantially.

I think the 7 should produce good results w/o over taxing the card and providing a better experience even though it's not a 100% match to the specs on the 10 panel. In this case a little restraint on the model might be the key to making it work well.

 

It doesn't care if your GPU is HBR2 or 3 or better if your screen only support HBR2 and need 4 lanes eDP. You can't say PCIE4.0 x8 and PCIE3.0 x16 have the same bandwidth if the GPU doesn't support PCIE4.0.
That being said, most 4k60Hz panel for laptop NEED 4 lane eDP because they doesn't support HBR3+. EVEN 2 years old 4k60Hz OLED panel are only rated up to HBR2, that's why they absolutely need 4 lane eDP to be driven at 60Hz.
For your information HBR3 is available for nearly 7 years but no manufacturer seems interested by making HBR3+ compliant display. Even 10 years laptop can be compatible with HBR3+, it all depends on the GPU (and MUX), the issue right now is display compatibility. HBR3 is available on GPU since Pascal (2016).
So no, you can't drive a 4k60Hz display with 2 eDP lane unless you get a very very special display (that I'm not aware of) that support HBR3 and only 2 lane eDP whatever the GPU you have.

 

Hello, just one last question before I receive my B156HAN07.1...

My dGPU (the Quadro M2000M) has an eDP 1.2 output, but the panel I just ordered uses eDP 1.4, so will it work ?

I read on the internet that DisplayPort 1.2 and 1.4 are both backward compatible but most of the cases I found were 1.2 monitors/1.4 GPUs...

So i'm asking to be sure

 

Should work fine. Just be careful not to flex things when moving them into / out of the lid.

When pulling the original out of the lid just apply constant pressure to release the tape seal. Might be handy to put a cloth down on the keyboard to catch it if it suddenly releases from the frame. Also, the cable is not going to give much play. Pulling the panel more like a book page flipping will allow access to release it from the panel.

I pulled mine a couple of times to gather info before ordering my new one so, when the new one arrived it was relatively quick to install. It took longer to pull apart the chassis / screws on the hinges to thread the new cable than it did for the panel to get into the lid. The panel bezel on mine just snaps into place and there aren't any screws to deal with. Check the manual on how to remove the bezel.

 

Hey ! So I just installed the panel and everything seems to be working fine

144Hz was applied instantly, I had no additionnal tweaking to do except applying the correct ICM profile found on the internet.



A little thing i'm worried about is that the 40 pins cable that I bought off AliExpress was a bit longer than the original one, so it's a little bit bent between the frame and the panel, I don't know if that could be a problem.

Except that I'm happy with the results, the colors, viewing angles and refresh rates are all as described

Thanks for all the help

 

You're welcome!

The small overage in the cable shouldn't be an issue. These things bend repeatedly in the hinge area with the opening/closing of the lid. As long as the end is locked into the socket on the panel it should be fine.