My laptop cannot boot. After powering on, I just hear fan noise without any signal on the black screen. the laptop has two stick of RAM and one harddrive. To rule out the reason, I removed them one by one and then powered on. But I have not found any difference before and after the removal. I did not hear any beep etc except fan noise. The screen is always black without any signal. Any one can give me some suggestion ? Thank you
Another thing that I had not told is that the laptop had been running for long time without shutting down. I do not know if this is a reason and which part is easily damaged.