P775DM3-G internal display drama [Help/Troubleshooting]

Discussion in 'Sager and Clevo' started by 5P4MB0T, Sep 12, 2021.

  1. 5P4MB0T

    5P4MB0T Notebook Guru

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    Hi,
    last week, my P775DM3-G's internal display failed.

    The screen just went black while browsing the web. No flickering (which I had experienced some a few weeks ago, though) or anything, just went black within the blink of an eye.

    Shut down the system and rebooted it, but the screen remained black and there was a faint burnt smeel, if only for a second, when the fans started. Windows did boot, though, as I could tell by the system sounds.

    Hooked up an external sceen via HDMI, and - as expected - everything worked fine. Checked HWiNFO64, and the internal screen was indeed gone.

    After some research, I ordered a Chi Mei N173HHE-G32 display as a replacement, after seeing several reports (like this one here) of it working with the P775DM3-G.

    Since my previous screen was a lowly FHD display with a 30-pin connector, I had to order a new display cable, too. Went with the 6-43-P7751-020-1L, which another user here had confirmed as working with the P775DM3-G's original 4K screen, so I assumed it should be fine with a 120 Hz display, too. Received a 6-43-P7751-221-1L instead, but the seller claimed it was fully compatible.

    Replaced cable and screen, but things didn't go as expected. The screen would light up, but remained all white. So I hooked up the external screen once again, checked HWiNFO, and - once again - the screen wasn't listed. It would light up depending on the Windows screen mode used, though, and brightness was affected by Windows power plans. Short version: Backlight worked, but apparently, there was no data connection?!

    I was a bit at a loss at this point, but remembered the smell mentioned earlier. Removed the cover saying "Don't touch" from the (supposedly) broken original screen, but I couldn't find anything looking "toasted" there, so I am starting to suspect something else might have died instead. A superficial check of both the graphics card and the MB did not yield any results (incl. no physical damage on the MB's eDP connector), but without knowing where exactly to look, this probably doesn't mean much.

    Some additional information:
    - As far as I can tell, all other hardware works fine
    - The N173HHE-G32 is Rev. C3. I couldn't find any definitive information about the revisions of those screens confirmed working.

    Opinions? Any known incompatibilities?
     
    Last edited: Sep 12, 2021
  2. Tech Junky

    Tech Junky Notebook Deity

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    Panels can be a PITA if things don't mesh up.

    The external display is a good indicator that the GPU is fine.

    Going black though w/o a reason could be the board under the warning label went out or a connector might have popped off the board causing it to go dark.

    The new one going all white though is more of a signal issue as it's getting power but, not decoding the proper signal to display graphics. i would try a different eDP cable or get an adapter for the one you had with the prior panel for the correct # of pins.

    If you want to dig deeper take the heat sink off and look under it for any signs of scorch marks on the MOBO. It does sound more like the cable is giving you the problem with the new panel though vs a bigger issue.
     
  3. 5P4MB0T

    5P4MB0T Notebook Guru

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    Thanks for your reply. Yep, definitely a PITA.

    Due to Clevo's "smart" design choices, I already had to take off the heatsink to exchange the LCD cable. They sure love hiding their screws in the most inconvenient places. :rolleyes:

    No obvious burn marks or suspicious discoloration on the upper side of the MB, where the eDP connector is located, or in the areas of the flipside exposed when taking off the heatsink. But like I said - it is hard to tell for sure without knowing where exactly to look. For the same reason, I'm reluctant to remove the MB completely to check the remaining hidden areas.
     
  4. Tech Junky

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    I forgot about the HS to pass the cable through the right path. SMH, they do make it difficult to diagnose some things. The service manual points out important things in the schematics though. If you need the link - https://repo.palkeo.com/clevo-mirror/ UN/Pw = repo

    When troubleshooting though they always say start at Layer 1 and that's the physical. Double check the cable on both ends to make sure it's fully seated. The only thing I can think of that might possibly be different in the PN/s is the pitch of the pins like AUO panels typically have a 0.4mm and everyone else is 0.5mm. I'm trying to think of anything that stands out from when i did my panel from FHD to 4K but, nothing really stands out as it was a straight swap from one to the other besides the cable swap from 30 to 40 on the panel side.

    If you have any doubts about the cable though check w/ kreplacement.com as they sourced the proper PN for me and I think it was maybe $15 for the cable.
     
  5. 5P4MB0T

    5P4MB0T Notebook Guru

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    Update: Disassembled the notebook once again, and upon closer inspection, this time using better lighting and zoom, I was able to spot this suspicious-looking little fella sitting right next to the eDP connector.

    toast-1.jpg toast-2.jpg p775dm3-g-esm-p70.jpg

    I guess this means the MB is to blame after all.
     
  6. Tech Junky

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    I think you might have a suspect with that. Should be a cheap fix if you do it yourself and a minor cost if you take it somewhere.
     
  7. 5P4MB0T

    5P4MB0T Notebook Guru

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    Any idea what to replace it with? Looked up the number printed on the part, but the search didn't yield any useful results
     
  8. Tech Junky

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    Might want to try a reseller to see if they have the module. Most of the markings on these things is generic and won't yield much on searches. @Meaker@Sager might have an idea on how to get ahold of one.
     
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  9. 5P4MB0T

    5P4MB0T Notebook Guru

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    Update:
    According to two people on a German forum, who appear to be competent, it is most likely a AP2821KTR-G1 (or at least a compatible part).

    Any objections?
     
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