Black Screen, Solid Light, No Chime

Please help me, I'm at the end of my tether..!!

I was using my laptop [Mac Book Pro, G4] just this afternoon, and it was running fine. I shut the lid down, packed it into my laptop case [didn't shut it down] put it in the boot of my car, and drove 20 minutes to the in-laws. Got to the in-laws, opened the lid, and got nothing. I shut the computer down via holding the power button for a short while, and left it for a few minutes. Pressed the power button back on, and everything seemed normal. The light came on, the drives started running, but no chime, and the screen stayed black. I left it for a moment, hoping it would kick in, but nothing. I tried this a few more times, but to no avail.

I've read many forums, and tried many things, but nothing has worked. I removed, and re sat the Ram, but that did nothing. Please help me fix this, I'm lost without my laptop..!!

Thanks.

Ok. Get your install disc and run Disk Utility to check the HD and permissions.
Also, if you can, do a hardware check. It sounds like you may have moved the HD while it was operational, which isn't a good idea. If you have you could be stuck, but see if disk utility can see the drive first.

Thanks for the advice, Kev. However, the fact that I could not see the screen [as it was black] - means I could not do those things. In the mean time, I tried re sitting the Ram again, which has worked..!!

Now that I've done that, are there any precautions I should take to ensure nothing goes wrong with my computer, outside of the hardware sections. [I will run Disk Utility now]