How did I kill four LaCie drives within hours?

I hope someone can help me make sense of this. I seemingly lost four external hard drives within hours of eachother. For simplicity, will limit the scenario to two for the moment: Lacie #1 and Lacie #2.

Initial Event:
Lacie #1 External:
I accidently used a different power supply adapter when trying to start Lacie #1 External. The one I used had slightly different amp output. Stupid mistake...

The Lacie #1 External power light flickered for just a moment, then went out. The drive never spun up, nor made a sound.

Result: Lacie #1 External would not turn on.

***
I had an identical Lacie external - Lacie #2 - so I thought I might try using that to recover data from the failed Lacie #1 drive.

***

Secondary Event:
Lacie #2 External

I tested Lacie #2 external with proper power adapter.
It powered up normally.

so

I removed the hard drive from Lacie #1 housing and installed it into Lacie #2 housing. Then I tested Lacie #2 external with proper power adapter. Lacie #2 light flickered, then went out. Why? I assumed it failed to read drive #1, which must be corrupted.

so

Removed hard drive #1 from Lacie #2 housing, and reinstalled drive #2 into it's original Lacie #2 housing. Tested Lacie #2 again, with proper power adapter. Now Lacie #2 would not power up at all, where it just worked fine two steps ago.

Final Result: Lacie #2 failure.

What happened here? I understand how the initial event for Lacie #1 could cause failure in both drive #1 and/or the Lacie housing #1. But how could that lead to the second event failure in Lacie #2? Is it possible that the bad drive from #1 somehow corrupted the Lacie #2 housing power? How is that possible? And since drive #2 was outside of it's housing when the failure occurred in Lacie #2, does that mean drive #2 is most likely healthy?

Any advice is much appreciated.

 

Stayed up late last night and worked it out. Here's what most likely happened.

1. When powering on Lacie #1 with the the bad adapter, it instantly fried BOTH the #1 housing logic board as well as the installed #1 hard drive logic board.

2. When I swapped in bad #1 drive into Lacie #2 housing, and tried to power it up, the bad drive somehow fed-back it's power failure into the Lacie #2 logic board, frying it as well. (I still don't understand why this was the case - why didn't it just fail to read the bad drive. Talkin bout a widow-maker) For anyone counting, that's 3 logic boards down.

3. My hunch was correct about drive #2 being healthy. It was out of the housing when Lacie #2 housing fried. When I reinstalled #2 drive back into the #2 housing, the housing logic board was dead, so could not pass on any further failures to the #2 drive.

4. Was initially unsure about how to get a PC/WXP box to read the former Lacie #2 ATA drive, as it was 320g, and the PC was older, but luckily, the bios could handle the drive size. All I had to do was remove a jumper on the drive, making it a slave drive. Once I did that, my PC read the disc 100%, with all the old Lacie formatting, partitions, etc.

5. As previously posted, my drive #1 was not running when it fried, it just failed to power-up, so I was almost certain all my data, physical disc, and heads were healthy. It was just the power. I stumbled upon a great website: http://www.deadharddrive.com/ - can swapping logic boards be that easy? - and just so happens I had a Torx socket sitting in my mini computer kit, unused for the last 20 years - so I popped off the healthy #2 drive logic board and installed it on the #1 drive, plugged that into my PC/WXP box and... WOOHOO - there's all my 320gb of data. I had recovered my own hard drive! The local data recovery shakedown joint was ready to charge me over a grand per drive (I'm sure they would have too, despite it actually being an easy fix, especially for experts in the field, this would have been nothing.)

6. I found a matching model/firmware drive on Ebay cheap - sectors are bad - but all I need from it is the healthy logic board - so I will swap that in for the burnt out board on drive #1. Recall, I actually had four total drives go down, so still have to find another cheap matching logic board for drive #3.

7. That leaves me sitting with four worthless LaCie housing shells, all apparently with burt out logic boards of their own. Plus I have to find permanent, networked new housing for the four hard drives. I don't want a whole new PC just for that. What to buy???