Hi!

( I didnt send them the hard drive by the way. )

Good idea. :-)

So I can see why I had the sporadic problem with the back light, but they
couldnt answer what was done to prevent this from reoccuring,
since this is the second time it has happened.

It may happen again. There may be an issue with the design of the laptop,
especially if the cause was in fact a loose cable. There may simply not be
anything that the repair staff feels that they can do about it.

Also, the optical drive(cd, dvd combo), was barely used, and never had a
problem.

I've seen this replaced on laptops under warranty even when the drive was
working fine. I'm not sure why it happens, but Compaq used to do it to me
almost all the time. If my laptop went in for any repair, it just about
always came back with a new optical drive.

Also, is thermal paste something that would get reapplied if done
correctly from the beginning?

Yes, it can be. If you take a laptop apart to any significant degree (see
http://12.206.251.215/d800fanrepair/ for my adventures) then you will end up
disturbing surfaces that mate with one another for the purpose of heat
transfer. To ensure that the heat leaves the system as intended, heatsink
compound (or thermal paste) is typically applied at each mating point that
is used for heat transfer in the system.

If you take a laptop apart that far, and if you are careful, there may be no
need to re-apply the paste/compound. For someone doing repairs on many
laptops, they may not have the time to be that careful, and since they don't
want to see your computer back for overheating damage caused by lack of
thermal compound, they will probably replace it as a matter of course.

William