Looks like you have quite the variety of drives, so that complicates things. Here's how I would proceed.
1) Build a new array, ultimately your goal will be a solid, reliable array. Don't reuse any of your old drives since we are going to try an extract data. Note that with this method of recovery, I don't think you can rely on any drive giving you back 100%, so if you have to do a rebuild on any given drive (assuming you fully recover that many drives), I don't know how reliable your rebuilt drive would be, either. You're welcome to try it. If not, maybe start with 1 Parity and 1 Data and work your way up from there. I'm assuming you know which of the old drives are data and which were parity. This method recovers the data treating the old array drives as JBOD.
2) Take say the STBV5000100, buy another exact model drive. Last time, I bought a used working drive off E-Bay. Test the newer drive, make sure it works and is reliable. Replace the bad drive's board with the new drive's board. Plug the bad drive into the server and use something like Unassigned Devices to mount it, then see how much data you can copy off of it. Once you have extracted as much data as you can, unmount and remove your bad drive. Swap the controller boards back. Bad drive goes on the shelf in case you need it for further recovery. The newer drive can be pre-cleared and added to the array. Repeat this step for all drives.
Something I heard was that reallocated sectors are recorded somewhere on the controller board. I heard it quite a long time ago, so I don't know if it is/was true. If it is, your recovery may involve accessing some incorrect sectors, which is why I think the data isn't guaranteed to be 100%, but again anything is better than 0%. This should also be non-destructive, so you could still use other methods to recover your data if you like.
I have not heard of the diode fix, nor have I ever attempted to alter a controller board in any way. All I have done is a straight board swap, and hope that any data losses are livable. Thankfully, this isn't something that I have had to do regularly, but it has worked once or twice.
PS: Dunno about the warranty, but I'd skip the soldering iron if you intend to go this route.