Strange... Exact same story here. Cracked my original 15" MBP screen LP154WP2(TL)(A1) and order a replacement and the company told me the (TL)(A3) would work. I put it in and no backlight (dim screen, still can faintly see image). I replaced my inverter board as well. I have a feeling the A3 might not be compatible with the A1 since we have the same story...