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OhYou-0 / thinkpad

BSD 2-Clause "Simplified" License
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What kit did you buy? I'd be happy aiding in getting something produced. #1

Open humanplayer2 opened 2 years ago

humanplayer2 commented 2 years ago

Hi @OhYou-0 !

I stumbled over your post on the ThinkPads forums, and it made my day!

I have the last month been in contact with an eBay seller that sold one of those kits, to determine if it could be used for the X301 and the 14" 1920x1200 AUO B140UAN02 which I have in my X1C gen 9 (I'd happily cut a bit of bezel to get that on my X301).

The seller and I had a prolonged conversation where they offered to make a prototype for 100 USD, but in the end, there was some issue their engineer couldn't solve. I'd be very happy to take up contact with them again based on your mod.

I'm not much of a solderer myself, and I also get confused by the compatibility of the different standards (e.g. will the X301 LVDS support eDP of 1920x1200? or Only 1920x1080?), but I would be more than happy to take contact to producers.

If I understand correctly, then the kit works as it should, but the mainboard-to-kit cable needs to be rewired---and that's it?

Could you share a link to the kit you've used?

OhYou-0 commented 2 years ago

I bought from here https://www.aliexpress.us/item/2251832650353585.html the markings on the back of the board are LTE-2KT COOERQI 02/2021

a 14in 16:10 is a good fit for the lid but I had no luck with it working on a NE140WUM-N63. I had backlight and brightness control but it remained black. The panel datasheet confirms it is electrically compatible and I tested the panel to be working in a t460s.

I see no reason electrically why x301 LVDS would not support 1920x1200, it probably would even do 1440p using the other kit. The 1920x1080 is strictly a limit to how the bridge chip is programmed.

the kit works fine with at least the panel I've tested, I only had to rewire the cable.

I'd love to see one made available to buy, it will be huge for libreboot users.

humanplayer2 commented 2 years ago

OK, yes, I see they sell two kits:

And OK, I see the NE140WUM-N63 is 1920x1200, so yeah, perhaps the WQHD kit would serve better for that. Nice that backlight and brightness works!

Super that you think the build-in LVDS would support at least 1920x1200. I'd aim trying at that, first, then, with a WQHD kit which I will order.

About the mod of the cable then, do I understand it correctly that what must be changed on the "X301-LVDS to Kit" cable is only:

OhYou-0 commented 2 years ago

no the wqhd kit is 40 pin 4ch edp, it will not plug into 1920x1200 as they are 30 pin. you could try and determine if the cable can be swapped but I am not sure if it would help as to me the chips look identical

have a look at the two schematics, you will see which pins need to be relocated . work is only done on the x301 side, it would not work to rewire the kit side as there are wires not present on x301 outputs.

humanplayer2 commented 1 year ago

Hm. Do you think that's something a 40 to 30 pin converter like this one could help with?

I took a good look at the schematics and now think I understand the cable better: It's the rewiring shown there, plus gender reversal of those two cables, right?