no power led, no keyboard and trackpad

hi there,

i have a lot of problems with my macbook air!

first the topcase had problems, so i bought a new one and let it be repaired by a computer shop.

the shop damaged the battery connector and put the blame on me.

so i have resoldered it with the help of the chair of microelectronic at my university. everything was working in an uncrewed status. as i was coming home to screw it, my problems restarts.

the keyboard, the trackpad, the backlit and the power led is not working again.

so i thougt it could be the lpd cable and have changed it. but it doesn´t work.

i was wondering also about, that the macbook is just starting alone, when i connect the ac adapter. what is also strange is that the keyboard and trackpad sometimes is working by pressing on the connector. and that the power button is also working with or without keyboard.

with an external keyboard everything is fine. so where is the problem?

can u help me?

thanks