Music Hard Drive Repair Project
10:00 AM: Replaced the hard disk in the drive that failed last night at the DJ Wedding Reception Gig. Copying the music library to it now.
05:30 PM: The copying of the music library to the new hard drive is finished.
07:00 PM: The external hard drive with the new drive I just installed still exhibits the same behavior as observed last night at the DJ Wedding Reception Gig. That behavior was that when turned on, the drive never completes the power-up sequence. It spins up just so far, then shuts down and repeats the spin-up again and again. It appears therefore, that the electronics in the drive enclosure have failed, and not the drive itself. So, I’ll no longer take this enclosure out on gigs. It seems that I have two good hard drives with complete copies of the music library on each.
09:00 PM: The electronics I swapped was the USB to IDE bridge board. However, there are other electronics in the case that have the power switch, the USB connector, and other functions. Since I’ve already tried swapping the USB to IDE bridge without success, I tried swapping the whole case; I took the new Seagate 250 GB drive I populated earlier today, and put it in the case for a 200 GB drive that I’m no longer using. So far, the 250 GB drive is working well, and I’ve tried powering it up and down several times. It started correctly every time. So, I’d say that this problem is fixed; I’ll scavenge the good parts I can from the defective case and throw it out.
12:30 AM: I put the original 250 GB drive (the one that acted flaky last night) into another old 200 GB case. It works great. So this project is complete, and successfully too. 
Tom