droped computer please help

My mother droped a computer down the stairs and the screen will not turn on.there are no beep codes.every thing inside the case was fine i did a basic check on every cable / component inside the case with no luck.the only thing unusual that i notice is that the hard drive light can stay on for hours as long as it is turned on.

pc brand IBM
os windows 98
processor intel pentium III

Laptop or desktop? From the screen I'd assume a laptop.

Have you tried connecting a different monitor to it? Alot of laptops have connections at the back to connect a monitor. You could try swapping the hard drive for another as well, there being no beep codes could just mean that the motherboard is stuffed as well or that there are no errors that it recognises. It could be booting up and then freezing because of the hdd not working properly.
Does it appear to boot up? Like if you can't connect a screen to it start it up and leave it for a few minutes and listen for any sounds that might indicate its finished booting up into windows like a lack of hard drive activity. Sort of like a minute or two of activity on the hard drive and then it winding down and stopping. Fans might also slow down.

Sorry I forgot some important information it is currently connected to one of my screens with rules out the screen its self as i know it works because ive been using it on a computer i'm building but any way it is a desktop and no there is nothing to suggest that it is booting windows the hard drive makes a few clicking noises it keeps running but when i listen to it there are no noises in the hard drive that indicate the arm is moving at all witch is unusual. i will swap the hard drive for one i have laying around to see if the fall damaged it.

And i will do some more extensive testing on the internal components to see if i find a bad part if swapping the hard drive does not work.

Thanks for your help i will post the results as soon as i can.
(edited)

no problem. The main reason I suggested the hard drive is that it has lots of moving parts that would be affected by a fall.

something is not right computer test as follows

different hard drive test 1 fail
comments none
another hard drive test 2 ??????
comments computer boots up properly alls well until computer freezes at post screen no error cods to read just freezes i shut off computer then computer will not turn back on i wait min then try again nothing i unplug power supply wait 5mins turn on with same hard drive as before same symptoms as mentioned before.

i will post test results for other components later.
i must sleep now. test later.

Doesn't sound good. Swapping out each component sounds the soundest plan to me though to identify any failed components. Only problem would be if some component has a problem in some obscure part that only appears after sometime if ya get my drift.. Like when there you have 2 sticks of RAM and the second stick is faulty it's not necessarily immediately evident.

hard disk from the computer test=good
windows 98 loaded successfully.

ram test 128MB=good

Looking good then A stress test might work well, or a benchmark test to stress out various parts of the system.. Sysmark?

video card test=ok
everything test=ok

i don't know why but i removed everything and put it back in and now it runs like new again.

thank you for all of your help you where great i wonder what was wrong in the first place though.

hmmm I had a similar problem not long ago with my father in law's computer where it wouldn't boot, I opened it up and made sure all the cables were plugged in fully. Tried booting up again and got nothing. Swapped cables around with no luck, put the cables back where they were and it booted up without a problem again. Still unsure what was the exact cause really there as I'm positive all the cables were plugged in properly.

really i wonder what caused it to happen thanks for the help

by the way the system i was testing the components with does not have a working operating system yet so i could not of extremely tested them
but that will be this system purpose once i install an
operating system onto it that why i put them all back in i could not do that test

i plan on getting linux and trying it though

Probably a wire connection loosened somewhere.