Optical Drive Converter

I purchased an ACER 5100 laptop about twenty months ago and at about 14 months the optical CD/DVD drive quit working. I had no use for it as I mostly moved files back and forth with a flash drive. Recently I purchased another drive to replace the one that was broken. Unfortunately, it does not work either. I have come to the conclusion that an internal connection from the motherboard is not functioning. Windows device manager does not recognize the drive. What is curious is that the drive is hooked electrically as the door will open and the drive light will momentarily turn green then yellow. I have both reloaded Windows Vista premium and reflashed the BIOS. It still does not see the drive. I am not ready to purchase another laptop and this one works fairly decent other than the optical drive. Now I have two Optical drives which I feel are operable. Is there a case of some sort that will allow me to convert one of these optical drives and operate it as an external drive through the USB Port? This would be satisfactory until I purchase another laptop hopefully, by the end of the summer. Thanks for you help.