I had same problem no chime blank screen did have power light apple logo keyboard lights.
Did SMC reset and it worked but weeks later same wont start up blank screen etc and now no apple logo light or keyboard lights and SMC reset not working.
I have researched and there is a fault with this model a1226 relating to video and graphics chip sets being cooked As they are poorly designed for ventilation this had a fix from apple back in 2011 free until 2012 cant find any more info.