HKC MB140CS01-4 is a compatible FHD lcd panel for T480 and most likely T480s thinkpad laptops.

https://www.panelook.com/MB140CS01-4_HKC_14.0_LCM_overview_60997.html

100% brightness still shows some flicker despite stating dc dimming in panelook. Tested using a T480, linux mint 21.3, full white rgb(255, 255, 255) patch. Not subjectively comfortable compared to 7i panel (see posts above).

(thorlabs pda100a2 detector at 20dB gain)

Zooming in with shorter 5ms timescale reveals 60hz flicker.

photon78s BTW, I tried a Nord N30 and surprisingly, it showed no easily detectable PWM at max brightness with the 240hz iPhone 14 Pro camera (which is otherwise good at detecting PWM on devices that other cameras don't catch)

Unfortunately, despite passing my PWM test, the screen still sucks IMO and is unusable for me. I'm actually surprised you can use it as your daily phone

The weird thing though is that it sucks in a totally different way than I was expecting.

Usually with "bad screens" on iPhones for example (on both LCD and OLED ones) I see "oversharpening artifacts with obvious color fringing, constant twitching motion everywhere, noisy looking white backgrounds, eyestrain that I can physically feel after looking away"

On the N30, I actually don't feel most of those symptoms in quite the same way, the screen feels more still than usual and I actually don't feel much "physical pressure behind the eyes" at all!

However, instead, what I feel is just intense blurriness when looking at the N30 display, nothing is sharp and everything seems to have "artificially softened" edges. The PPI of the 1080p display is great in theory and I can't see the pixel grid, but despite that, everything looks blurry. There also seems to be weird very subtle black shadows around all text and borders/dividers.

(It's a totally different feeling from looking at a "low res" display that "still feels sharp but is just pixelated looking". The N30 is actually blurry and makes me feel like I need glasses even if I bring it close to me)

After using the N30 for just 20-30 minutes I feel extremely tired to the point I want to fall asleep and lots of brain fog/confusion.

The symptoms are actually very unique from my typical FRC, PWM, or "Apple device/AMD/modern Intel graphics post-processing" symptoms — but still affect reading and productivity just as bad

The main symptom it does share with Apple devices and modern Intel graphics is the false 3D effect, however it's more subtle than usual. Didn't notice it at first but became obvious on certain content.

(The presence of that effect is already enough of a dealbreaker to make me return it IMO)

After taking a break, I looked at my old Redmi 3 for 10 minutes to reorient myself. After that I already felt like I had a decent amount of my energy back and I could finally see clear and normally again!!

White backgrounds are also very strange on the N30, because they both feel harsh and not harsh at the same time. They aren't noisy or flickery feeling like on iPhones, but they still feel way too bright compared to everything else.

In general there's also way too much reflectiveness to the N30 display.

Modern iPhones use some kind of oversharpening effect. Meanwhile, the N30 also definitely has post-processing but causes undersharpening instead.

Meanwhile, the 720p display on my Xiaomi Redmi 3, which actually has lower PPI (and even has some mild PWM at max brightness), is totally fine and everything appears as crisp as it should.

I actually put them side by side and the N30 was so obviously blurry compared to it.

I even showed the N30 to a friend who's otherwise not screen sensitive at all (they use an iPhone 12 that I can't even stand looking at) and even they said the N30 looked blurry and felt difficult to read

To repeat, it's not because of the PPI or resolution, because the physical density is high enough where I can't see the pixel grid.

It's the software, GPU or panel controller that's doing something weird. This is not usual FRC or flicker but something different

OxygenOS 13, HW overlays disabled, same experience with both the 60hz and adaptive 90-120hz modes

    DisplaysShouldNotBeTVs what phones don't give you any symptoms just the Redmi 3 or? I've tried so many phones lately and all are brutal sadly. Next one is gonna be the cat s62 pro I'm gonna test soon

      DisplaysShouldNotBeTVs

      Thanks for the insights. Most likely we have different sensitivities and I agree about the weirdness and blurriness to it. I just turned on my old redmi note 6 pro which was being "borrowed". The redmi note 6 still feels superior to the N30 edit: in terms of text rendering but I see visible gray flicker when filmed with the n30 slow motion mode. The note 6 is still running android 9 and MIUI 12.01Stable.

      DisplaysShouldNotBeTVs After using the N30 for just 20-30 minutes I feel extremely tired to the point I want to fall asleep

      I have noticed this with another person looking at my phone just yesterday. He didn't attribute it to the phone but just said he wanted to go to sleep afterwards. Then this is also the unit variance in panels etc. How is your iPhone 14 Pro?

      It's the software, GPU or panel controller that's doing something weird. This is not usual FRC or flicker but something different

      Also, just the PWM waveform itself looks complex (multiple frequencies) and has greater depth not like the other phones (redmi note 6, moto g7)

      Nord N30 PWM at 5uS time window showing 71.7 kHz flicker and the weird overall shape

      Xiaomi Redmi Note 6 Pro

      Another "bad" phone for some but not for others? PWM waveform at full backlight brightness. Compare with OnePlus Nord N30. Same measurement device settings for comparison.

      N30:

      Moto G7 (LineageOS 20) backlight flicker

      This "might" be a promising option. edit update: See the Vp-p (peak to peak) of 5.20mV in the lower left corner (cyan section). This is the amplitude of the flicker signal and is the lowest so far. The "bad" Nord N30 is over 42mV (over eight times higher)

      I think it would be even more helpful to add frequencies and flicker percentages, too.

      jordan

      what are the phones that don't work for you beyond what you've mentioned previously? have you noticed any commonalities and correlations across these bad devices like the screen type, flicker depth, frc pattern, os versions? perhaps any unexpected commonalities.

      have you tried putting electrical type over any front facing cameras and any IR infrared light emitters?

        photon78s
        I'll just list all my bad mobile devices:
        iPhone XR, se 2020, iPhone 11, xiaomi 13, Xperia 1 V, honor magic 6 pro, honor 90, xiaomi 13t, edge plus 2023, moto g stylus 5g, xiaomi pad 6. I think that's all, if I forgot any ill edit. I'm currently using the honor 90 and it's making me feel zombied/disconnect feeling. The higher pwm devices seem to be a little better in darker lighting conditions I noticed but none are symptom free. Every iPhone gave me instant dry eye and so did the xiaomi 13 (non T) which I'm assuming is from dithering/frc? Every device gives me blurry distance vision and slight double vision. The 13T wasnt perfect, I was still able to function but it started compounding and affecting me sadly.

        Also something recently made me feel really not so well which I think was when I was playing around with the brightness on my uprtek mk350n light meter(visible bars with 1/4000 SS)

        Devices up next to try is cat s62 pro, vivo x100 pro and daylightco tablet. I did also preorder the light phone 3 but I'm not sure if I should cancel that.. they say it's true hardware dc dimming but not sure if the refresh dip may affect me of the grayscale OLED it uses

        Also did try that humane ai pin phone which the "trust light" alone made me feel awful since it color flickered so I returned it. The laser projector seemed to bug me too on it.

          jordan

          Slow motion footage show the front ir sensor flickering on many phones including the ones I've tested above. Covered up just to be extra cautious.

          Interesting and perhaps disappointing that the light phone went from e-ink to oled…

          dasung has the e-ink phone monitor but last I checked it was still buggy and awkward to use…

          https://shop.dasung.com/products/dasung-6-7-e-ink-phone-monitor-link

          photon78s To summarize the information you shared (and the links), laptop displays tend to have generic connectors, with only a few common variants? So finding compatible replacement panels is perhaps easier than I envisioned.

          It appears that these panels (compatible with the Thinkpad T480) incorporate their backlights, rather than having the LCD only which would require re-use of the original backlight (like recent MacBooks). Is this correct?

          Did you ever personally try a 6-bit panel in your Thinkpad to see how Windows handles this? As I stated in another topic, I tried a few HP ZBook models and they seem to have 6-bit panels (with Windows recognizing the displays as 6-bit), and the pixellation and colors suggest the screens are running at true 6-bit in Windows. I am currently exploring how this is triggered. Unfortunately, EDID manipulation of an external display to set it to 6-bit color does not do the trick. I am assuming most laptops will dither a 6-bit display to 8-bit, but I am not sure whether this is due to the inherent circuitry, BIOS/VBIOS, or something else.

          The HP ZBooks do not feel like quality laptops to me (loose trackpad buttons, etc.), but if the true 6-bit displays could be replicated in better-built laptop like a Thinkpad, I would be interested in trying that. I had a Thinkpad T480 laptop in the past, and my only real complaint with it was the low keyboard rollover count, which made it beep at me if I typed too fast.

            macsforme To summarize the information you shared (and the links), laptop displays tend to have generic connectors, with only a few common variants? So finding compatible replacement panels is perhaps easier than I envisioned.

            I think you are correct. With the T480, I think their are three versions of eDP connectors corresponding to touch screen, FHD, and WQHD panel types. Don't know about other laptops. I am waiting for 01YR503 type cable for WQHD and I swapped out the touch screen eDP cable (01YR502) that came with my used T480 with cable type 01YR501 for testing the FHD HKC MB140CS01-4 which imo is not a safe panel due to PWM and FRC unfortunately. Once you have all three types of display cables, then you are free to try the full range of potential panels.

            macsforme It appears that these panels (compatible with the Thinkpad T480) incorporate their backlights, rather than having the LCD only which would require re-use of the original backlight (like recent MacBooks). Is this correct?

            Yes, the backlights are incorporated into the panel. If you are very careful due to the sensitive ribbon cables, you could take out the backlight and can convert it into a solar or even incandescent display. Instructions on spectrumview.com

            macsforme Did you ever personally try a 6-bit panel in your Thinkpad to see how Windows handles this?

            I want to try this but the 6 bit touch screen panel that originally came with the laptop (R140NWF5 R6) broke due to my clumsy fingers. It was also a terrible panel in terms of PWM.

            By now I've owned or had the chance of using T43p, T500, W520, T480s, and now experimenting with T480. My best eyestrain free recent memories was the T480s with B140QAN02.3 in 2018 running earlier windows 10 of 2018-2019. That was also running on intel UHD 620 iGPU. This corresponds with what DisplaysShouldNotBeTVs posted. Maybe it was also panel lottery.

              7 days later

              photon78s id imagine it could make it less of a problem possibly since the refresh is so high? 🤔

              Hopefully someone can try it 😅

              photon78s

              In theory, the pixel inversion will be around 240Hz so will also be harder to capture. If someone is less sensitive to very high frequency flicker, this might be worth a look.

              dev