I recently had to almost completely disassemble my laptop, and Inspiron 1545, to replace the fan. After putting it all back together, I now have a new problem. I have to press the power button with more force and for a longer time than I had to prior to replacing the fan. I now also have to press the button 3 or 4 times before the laptop will power on. The obvious question is, did you put everything back the way it was ? I sure think so. Everything else works. The AC power adapter and battery are both functional. I pulled off the power button cover and pressed the little white power button that is connected to the Power Button Circuit board, and it had the same problem, so it does not look like the power button cover was not seated properly. I also disconnected and reinserted the power cable on the Power Button Circuit board, thinking that I may not have reinserted it properly the first time. That also did not help. Maybe I need to replace the Power Button Circuit board.
So I ask the forum for help - what do you think it could be, and what should I try next ? Thanks for any assistance.