We have an Inspiron 1501 that was operating fine. We heard a pop in the room it was and have no idea if the sound came from the unit or not, but it will not boot. Well, it may be booting but I cannot tell as there is no display. When starting, the lights flash as usual, but upon pressing any keys on the keyboard, first they click, then the click becomes a beep. This beep will sound every time a key is pressed, regardless of which key.
The unit was on and running at the time, but in sleep mode.
Sounds like the laptop is dead. A few things can cause a pop, one of them is a capacitor that full blows out, although it takes a pretty good electrical surge though one to cause that. Power supply or the power brick can also go out like that but they would not cause they keyboard issue. First thing to check is the motherboard.