Mini/Leopard: Suddenly not chiming or recognizing ext FW HD

My 512 MB DDR SDRAM Mac Mini (1.5GHz PowerPC G4) has worked fine for 2 years hooked into a "Mini Pal" external HD (has the same exact footprint, sits directly under the Apple Mini, but is made by Acomdata), which is hooked to the Mini via FireWire (along with a USB plug). Whenever I would boot the Mini, it would give its characteristic CHIME directly from the Mini rather than from the ext speakers I had hooked up to the earphone output. It would then mount the two partitions of the "MiniPal" and life was good.

Then I added a new iMac to my LAN and cloned all the Mini's data onto the iMac, and the Mini took on its future role of being just a server with its own internal HD, its external HD(s), and its hardwire-connected printers. The Mini still booted normally (with CHIME) and showed the two Mini Pal HD partitions as before.

Earlier today I added a .5 TB LaCie external drive, whose new role is to back up that new iMac's HD over WiFi, to the .5-TB LaCie attached via FW to the Mini acting as a server.

I hooked the LaCie drive into the Mini by plugging its FW I/O into a spare FW socket on the Acomdata "Mini Pal" drive. In doing so I was extremely careful to do the hooking up with all power off, and never jarring the Mini Pal.

Upon rebooting, I expected to see the Mini Pal's two existing partitions self-mount, along with the icon for the newly-daisy-chained LaCie HD.

Imagine my surprise to hear the Mini NOT emit its characteristic CHIME upon being rebooted. "Hmmm..." I thought.

What was worse was that I did NOT see the "Mini Pal"'s two HD partitions show up in the Finder. However, I DID see the LaCie's new ~.5TB external HD show up! This seemed odd to me because the LaCie's FW connection goes THROUGH the "Mini Pal" FW sockets and thence to the Mini itself. Another of the Mini Pal's FW sockets is connected to the Mini (along with a USB plug).

No amount of unconnecting, reconnecting, powering up or down the HDs or complete rebooting seems to wake up the Mini Pal, which (while it remains perfectly happy to pass daisies through itself to and from the LaCie) does not seem very pal-ish anymore because while doing this, it doesn't disclose or mount its contents.

I don't think the Mini Pal has crashed physically because I do hear its drive spinning up, softly vibrating, and making a track-seeking noise or two... especially so because I was fanatically careful of it while hooking in the new LaCie drive... Disk Utility doesn't seem to see anything related to the Mini Pal either. It seems too much of a coincidence that the thing should crash NOW or otherwise cause my problem, but the problem still just cropped up.

Interestingly, even when the Mini Pal is powered down, I apparently can "look through its FW plugs" and see/mount the LaCie downstream.

Anyone have any thoughts on how to revive the Mini Pal? And what happened to my Mini's boot-up CHIME sound? Are these two problems related? Tnx for any advice...