x1 yoga 3rd keyboard compatibility black vs gray

[timop]

Hello,

I was recently able to source OEM palmrest + keyboard in gray colour to replace my random language keyboard and palmrest that had small piece broken off next to right side usb port. Spare part # 01YN924

But there is only one issue: Left Fn + Ctrl keys are not working for some reason. I have been trying to figure it out and I have checked all connections multiple times and all but the functionality is always similar. Mechanically everything is fully compatible but the single key just does not work.

Haven't removed the actual keyboard out from palmrest part yet but otherwise I've triple checked everything and have not been able to find anything. Even popped the keycap and checked under it and everything seems to be working.

Does someone know if I am missing something? Or is this just a feature and I must reconsider what to do?

[dcfbf]

While there is a difference in palmrest, the keyboard is the same between the black and the gray models and will be compatible.

Chances are, the keyboard traces for the fn and ctrl keys are messed up.
You can try to reset your bios to default settings to see if that can fix it.

[timop]

Thanks for quick reply. I purchased OEM spare part directly from Lenovo. Luckily it was dirt cheap.

It seems that in addition to Fn key not working at all the laptop is not turning screen off no matter what setting I have in Windows 11 and how long laptop is idle. Also bios reset did not fix it and based on CMOS battery voltage the BIOS has been reset automatically during each connector reattachment attempt anyway.

I'll probaby investigate the traces at some point and try to figure out if I am able to find something that explains the issue with the key. If anyone knows something about the key matrix or similar info, I am interested.

Ps. It also seems that the keycaps and hinge mechanisms are not similar between my original keyboard and the spare part. There is something like ~1mm difference at mounting tab locations.

[RealBlackStuff]

Different keyboard manufacturers use different parts.
And then you can also get Chinese knock-offs...

[timop]

I checked with magnifying glass and the connector fits properly to the flex connector, the pressure marks are approximately centre of the connector pad.

I was able to find random repainted keycap keyboard without palmrest relatively cheaply and the keycaps were compatible with new OEM keyboard and it also worked with the motherboard directly. So I got everything working now.

Currently I am thinking about sourcing the SMD connector part from somewhere and investigate the keyboard matrix between working and not working keyboards with arduino just in case someone else faces similar issues and there is something that can be done.