"The DS won't turn on. Green light flashes for a second."에 답변Another year later the same problem occurs. It turned out that, for me, the top screen's ribbon cable was *slightly* loose. By 'slightly' I mean it was less than a milimeter from the furthest point. I suggest you reinsert all your ribbon cables.
"Tool needed to remove bottom of A1048 keyboard?"에 답변I've used a 1.3 hex bit and according to what I saw it's the proper one.