(power on self test) and you see stuff on the screen, no matter how short , do the following: (this checks for a software problem)
when booting up press F8 and when you get to the menu, boot up into safe mode,
then restore the pc back to a date before you had the problem, and/or remove any program you installed prior to you having the problem,
if that don't work Try a bootable anti virus disc, use it to check for any viruses ,
if not try a recovery disc, or operating system disc ,
both disc's will try to access the hard drive. if they do not work, (nothing has changed) nothing comes on the screen.
laptop does not post: (then it is a hardware problem)
- try the following first.check battery is seated correctly and that the power pack is functioning,i
- f the battery has gone flat and the power pack is not working ,the laptop will not start.
- Remove any hardware you may have installed prior to you having the problem.
- remove the screw(s) holding the cover plate on the back of the laptop where the ram lives and remove the memory sticks,
- clean the gold edges both sides, with rubbing alcohol or a pencil eraser, and re-insert them, (not an ink eraser as it will do damage)
- swap them around if you have more than one,
- try one at a time.
- if you only have one, borrow one from a friend or try the ram in your friends laptop ,if that's possible, or
- get a friend or family member to download a "memory chip diagnostic's" program such as memcheck 1.70 and boot up of it ,it will check your ram ,if not
- take the ram to your local pc shop and ask them to check it for you (they may do that for you)
- if you can establish that the ram and power pack is ok, and anti virus and recovery /system disc's do not work,
- it may be that the motherboard or the cpu is failing
- Generally a dead hard drive would not stop the laptop from posting.
good luck with that and let me know how you get on.