A year ago I suddenly lost the use of the original 80GB hard drive on my Dell D430 notebook, my "Dinky Dell," which had become my favorite laptop for quick jobs such as looking up listings in my DVD catalog before watching a movie. I bought a SSD drive, but it didn't work, so I returned it and got a refund. Then I bought a 120GB HDD, but the 430 refused to recognize that, too. The latest drive I've gotten for it matches the factory original, a Toshiba 80. It was guaranteed to be functional. But my 430 has rejected it, too. 

Now I'm convinced that there's some other component inside the 430 that has failed and is preventing the circuit from recognizing any HDD, no matter what it is. I'm sure the original Toshiba 80 is still good. But this mystery component, perhaps the BIOS chip, or some capacitor or resister somewhere along the line between the HDD and the CPU has gone to pot, leaving my 430 unable to recognize a HDD.

My worry is that this unknown component, this occult mystery device, cannot be located, even by one of the 430's original designers, and replacing it will be tantamount to capturing a will-o'-the-wisp on a dark night in ancient Scotland.