Keyboard internal cable doesn’t work

Hello,

I have a MacBook Pro 2016 without touchbar (A1708). I decided to change the battery and to replace the thermal paste on cpu. It worked, but after I replaced everything my keyboard doesn’t work.

I thought I broke the internal cable for the keyboard, so I changed it, but same problem. Actually I found that the problem is that one part of the cable doesn’t stick on the motherboard. If I press that part and turn on the laptop the keyboard will work. But as soon as I release the pressure I can hear a sound of « unstick ».

I tried to contact the seller from where I bought the cable. He is saying to put regular tape, but there is no way that regular tape put enough pressure on it.

Do you have any idea how to have the cable permanently in contact of the metal part of the motherboard ? Or the problem comes from somewhere else?

Below pictures that I tried to take:

This is the part on the cable which doesn’t stick to the metal part on the motherboard. I already removed the plastic around the fan which was hiding the cable. When I put the plastic back, actually there will be another cable on the keyboard cable. That cable is tough and I thought that it was it which make pressure but I didn’t succeed that way neither.

This is before I unmount the plastic I was talking before. The keyboard cable part which doesn’t stick is circle in red. It’s actually under another cable.

The red circle is the part of the cable which doesn’t stick on the motherboard. I say stick because I feel there was really kind a glue on it. When I press then release my finger, the cable will go up just a little bit, and no more contact with the motherboard.

I have shown some pictures to a friend, he thought that the part I circled in RED might not be a connector, but just something to help to stick better on the motherboard. He thought that when I pressed that part, it was making better contact where there is the connector (circle in GREEN) and there was no link with the part circle in RED.

My next try is I will buy some strong tape and try to tape different parts to see how it works better. Now that I checked more the connector, it's true that when I was removing the motherboard from the laptop, I forgot to remove the keyboard cable (because it didn't see it under the right speaker cable). So maybe I did something bad to the connector circle in GREEN?

Also when I remove the plastic part (which belongs to the right speaker) which covers the keyboard cable, I noticed that the 2 speakers and some screw were oxidised, I wonder if the connector circled on GREEN wouldn't be also oxidised. Don't know if it worth a shot to put WD40 on the connector.