Im having some trouble getting my chip setup to work. Any and all help appreciated. Im pretty new to this so...bare with me

Installed it first using hackdabox tutorial, however there was a problem with the connection on the tiny cable in LPC rebuild. Got that fixed but it still wouldnt work. MS dash started up fine, but when i tried starting it in chip mode it just went black.
I tried nailing down the problem with chancers tut, and i grounded BT, and L0. Now as soon as i insert the pw cord it powers up and still wont work, also cant turn it of with pw button. I get black picture, the chip wont boot.
Ive redone the soldering, and it looks OK to me.
I would appreciate your input. I would be able to take some pictures of it if needed.
Thanks,
Martin