It is indeed called a CRT, and ya, sounds like it's toast.
Anyway, back to the problem at hand. I'm sorry Monika, it sounds like you've either got a connection loose (cable) or hardware failure here. We're going to have to open up the computer. It IS possible to damage the computer with the case open, so if you don't feel comfortable doing this, I suggest hiring a tech to take care of the problem for you. I'll include the directions below if you do decide to try your hand at some computer repair.
First, unplug the computer from the power source and remove any cables attached to the box (Slang for a computer case and it's contents). Place the box somewhere with room to work. I HIGHLY suggest getting an antistatic wrist band for working inside of a computer from your local computer store, this can prevent static from arcing from your fingers to the components inside of the box, which can damage and destroy them. Remember, even if you can't feel the arc (above 100v), you can still damage the computer and not know it. That's all for safety, moving on.
All cases open differently, so I can't guide you on that, look around it and find any screws that might be holding the side panels on and attempt to remove the panel so that you can see inside the computer. Again, it's hard for me to say how to do this, you may be able to find instructions off of Google for this.
Once the case is open, look for your DVD drive and find the ribbon cable attached to the back. There will also be a power supply with several separate wires going into it, but this isn't the problem as the tray can open/close. Check to make sure that the ribbon cable is completely pushed into the socket on the back of the DVD drive. Next, follow the ribbon cable back to the motherboard (Big circuit board attached to the reverse panel usually). Again, make sure that this is properly attached to it's socket.
If the ribbon cable is completely disconnected from either of these, you're going to have to find the correct cable. It is called an IDE cable and you can search for images of them on Google. Find the ribbon cable that I'm talking about. If it is disconnected from the motherboard, you'll need to find the correct socket. There should be other ribbon cables attached to the motherboard as well, such as the one connecting your floppy drive. The IDE cable should attach near this one. If you look closely, sometimes the motherboard will label the socket, usually IDE0, IDE1, etc. Find the socket with the lowest IDE number on it and insert the ribbon cable. Don't use too much force, it is keyed and will only insert the correct way, look at the plug and the socket to figure out how it goes in.
If the cable is disconnected from the DVD drive, identify the correct IDE ribbon cable. Find the furthest plug from the motherboard-attached end and insert it into the IDE socket on the back of your DVD drive. This is keyed, so examine the cable and the socket so that you insert it correctly, it won't go in if it's wrong.
Now, once you have this all done, close up the box and reconnect all of the cables on the back of the box and boot up your computer. Test to see if the drive is visible now. You may have to go through the steps mentioned in the previous post to "Scan for hardware changes," and may need to reinstall the driver.
If none of his works, well, your drive is most likely toast and you'll need to replace it. If that's the case, I'm sorry, it sucks and I've been in that situation before. Luckily, drives are relatively inexpensive. I suggest buying one from newegg.com.
Hope this helps Monika, if you need further help, you may want to just email me.
ryan.roler (at) gmail (dot) com
Good luck!
Ryeguy
January 2009