well here we have one with a weird ass issue. after a few seconds of powering on, it shuts down. whenever its in boot selection menu, recovery, diagnostics, or booting to mac os. if i remove trackpad flex, then it works just fine, but obviously no trackpad or keyboard. i tried another know good whole topcase and bottomcase assembly and still same issue. i tried flashing a clean me bios, and still the same issue. so where should i go from this?