Non-responsive hard drive - help?

All, mea culpa, didn't teach the kids about backups before trying to teach them Pascal on my Mac Plus. Sigh. Broken component is the hard drive from a La Cie Tsunami external enclosure. Drive is a Quantum Prodrive LPS, 240 MB capacity, part number (I think) GN24S012 Rev 05-J. Drive failed while in use, so it's not termination; another hard drive (Seagate ST31230N) in the same enclosure appears to format OK (that's as far as I've gotten to date), so I don't think it's the SCSI interface in the Mac Plus or the Tsunami power supply. (Despite one inadvertent 120V discharge to the anti-static on the inside of the Tsunami case!) Drive no longer appears as a boot drive on the Mac Plus SCSI chain, nor as a boot drive to a Mac II, nor as an accessible drive to either the Plus or a Powerbook 3400. Another drive (Apple CD 300) placed downstream of it (and termination rearranged appropriately) *does* appear to the 3400, so that's another data point that it's the Quantum that's broken and not the enclosure or the SCSI cabling/termination. Drive *does* make spinning-up and head-seeking noises (once per power-up). LED indicating drive attention does flash, *once*, as computer boots up. 5V and 12V supplies to drive look OK to my old analog multimeter. When running with case open and parts spread out (now more carefully insulated), one chip on the Quantum controller board gets pretty hot pretty fast. That chip is marked 2J4 HA13476 and has a couple of "wings" in place of the middle 4 or so legs that would normally be on either side of a regular DIP package. I haven't gotten an ESR meter yet (I *really* need one of those), and have not attempted to survey for bad caps on the Quantum controller board. Questions: 1) Is the HA13476 expected to be pretty warm in use? 2) What is an HA13476? Is it unobtanium, or replaceable by someone of my meager soldering skill? 3) Anyone have a matching drive that I could get at reasonably low cost to try exchanging controller boards? 4) Any suggestions for further trouble-shooting and/or repairing? I'm proceeding with the Seagate, and will restore from my last backups, but I know I won't get the kids' Pascal code, so I'd like to try to get this HDA running again if at all possible. (Plus there's the nostalgia factor - this was our main home system until 1997 or so, long enough that people were making fun of us about it.) (And yes, our current main home system is *almost* on topic. It's the 3400 referred to above.) I'm reading classiccomp on digest, and have an hellacious travel schedule through next February, so my responses will be sporadic at best. Apologies in advance for that, but any advice is well appreciated! -- - Mark 210-522-6025, temporary cell 240-375-2995