w550s/t550 LCD screen replacement - brightness set at max.

Discussion in 'Lenovo' started by giggidy, Apr 5, 2015.

  1. adrian_sa

    adrian_sa Newbie

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    So I found a guy with a X250 and Ubuntu, he only needs to dump his EDID with edid-rw? How to later edit the file if he is using a HD panel and I want to install a FHD one?
     
  2. miomi

    miomi Newbie

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    It's better if you can find EDID dump from X250 FHD. You might still get away by overwriting the FHD panel's EDID with whitelist HD panel EDID dump, but I am not sure if there will be a negative impact with this.

    Btw, can you confirm X250 really has panel whitelist ? Because currently we only know models like T450, T450s, T550, and W550s that has panel whitelist.
     
  3. adrian_sa

    adrian_sa Newbie

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    The X250 does have a whitelist, I installed a 15.6" 1080p TN panel and brightness control didn't work. Bought mine X250 bare, just the case keyboard and motherboard.
     
  4. miomi

    miomi Newbie

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    Thank you for confirming. Shouldn't the X250 use 12.5" panel?

    So it seems almost all thinkpad models with intel core 5th gen (broadwell) has panel whitelist issue. The only broadwell models that needs to be confirmed are:
    X1 Carbon 3rd gen
    E450
    E550

    There are also amd variants of the E series: E455 and E555. But since they use amd chip, I think there is no whitelist on them.
     
    Last edited: Oct 9, 2017
  5. adrian_sa

    adrian_sa Newbie

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    That was just a quick test. Since I would have problems with a third-party panel anyway I ordered a BOE NV125FHM-N62 because of the better contrast. The panel looks amazing but of course the brightness control doesn't work. I bought a SOIC8 test clip but couldn't get a reliable dump of the BIOS. There is a thread on bios mods forum on how to disable the whitelist.
     
  6. 4est_v2

    4est_v2 Newbie

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    Can't we just cut the write protect pull-up pin of the EEPROM and then just flash it from linux?
    why won't that work?

    likely the pull-up is one of the small circuit o the pcb visible here
    http://postimg.org/image/yqoutrng7/

    so just receive the panel, cut the pull-up circuit, install in the notebook and flash it from linux
     
  7. adrian_sa

    adrian_sa Newbie

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    I flashed my BIOS successfully, I had to to use Ubuntu and flashrom for it to work.

    Poslano sa mog Redmi Note 3 koristeći Tapatalk
     
  8. notjaykay

    notjaykay Newbie

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    I realize this is a somewhat old thread, but I wanted to just say thanks! I had recently purchased a used T450 with a broken touchscreen with the thoughts of replacing/upgrading the panel with a FHD one. Low and behold, I didn't realize how drastically different the LCD assembly is in a touch vs non-touch model. That being said, I was still able to remove the broke touchscreen, salvage the frame, and install a new LP140WF3(SP)(D1) in it's place. It's lacking the bezel, but it works! However I was unable to control the brightness in Windows 10 and then came upon this thread while searching for options.

    When I first tried using edid-rw in Linux Mint, I wasn't able to locate anything on the buses. Using i2c, it did spit out some garbled panel data. Thinking maybe if I updated my BIOS (I was on 1.19) it might possibly have been added down the road, I reinstalled Windows and also updated my BIOS to the latest March 2018 release (can't remember version). Alas, that didn't fix anything. I contacted the merchant I purchased my panel from and they suggested I try the EDID override which didn't work. I then fired up Linux Mint again and actually was able to read the panel at bus location #4. I used Miomi's post about edid-rw. and I discovered my panel was not write protected. I flashed over the appropriate BIN and redumped the EDID and found everything had taken. I fired up Windows 10 again, went into Device Manager, updated the driver, and "Generic PnP" switched over to a "Flexview 1920x1080" entry and I had brightness controls!

    So thanks again!

    For what it's worth, when I was on BIOS 1.19, I was able to adjust brightness in BIOS (and in Linux Mint). When I updated to the latest version, I lost brightness controls in BIOS. However, I was still able to adjust brightness in Linux.
     
  9. bololabich

    bololabich Newbie

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    I've red a big chunk of this thread but I don't know if I get it all correctly, so I've got x240 and installed non-branded LG LP125WF2 SP B4, brightness works on linux and in uefi but not windows so the only way to fix it is to try flashing EDID?
    Is it enough to change model name from LGD048A to the closest specs LEN40E4 and generate bin file of my LG display or should I have some data from the same display with lenovo branding - which is impossible as they only used B1 and B2 and I've got B4.
     
    Last edited: May 13, 2018
  10. t456

    t456 1977-09-05, 12:56:00 UTC Moderator

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    No, you need to flash the full edid, not just the id. Doesn't matter that the B4 was not an official panel, the only thing that is important is that one of the whitelisted edids from the bios has compatible parameters with the non-Lenovo branded panel.

    Only extracted the edids from the T450(s), T550, W550s, Yoga 260 and Yoga 360. If you can upload the latest x240 bios somewhere then I'll try to extract them and find out which is the best match for the SPB4.
     
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