Every error screen is happening! Can't pinpoint the problem

30gb iPod video, version 5.5. I implore you to please read all of this because I am at a loss and have read just about every forum so far. The problem is that I am not have any one particular problem / error screen... I'm having them ALL.

BACKSTORY AND WHAT I'VE DONE:

Last fall, I left my beloved iPod video outside and it rained. It didn't get submerged in water, but it definitely got wet. Filled with woe, I tried to fix it by opening it up and letting it dry, but to avail. I was able to turn it on long enough to save the songs via Sharepod, but otherwise it was dead.

Fast forward to this summer. I have some free time so I thought I'd try to fix the little guy. I bought the Tarkan iFlash to replace the the hard drive as I thought that was the problem. I am using a SanDisk 32gb class 10 card that is, according to everything I have read, compatible with the iFlash. It has been formatted.

So I wait patiently for my parts to arrive and when they do, I install them.... only to (like so many before me) accidentally break the battery connector on the logic board. Filled with woe once again, I scoured the internet for a 820-1975 version (which are weirdly hard to find). Ifixit was out of stock. Finally found one in China. Waited with bated breath a month for it arrive.....

And when it did arrive, it was A %#*@ 1763 MODEL. After cussing a lot, I did some research and found that most people said that on a 30gb, either can be used, I just won't have the search function anymore, so I gave it a try and installed it anyway.

So to recap: I have a new (albeit different model) logic board, new SSD, and a new screen. Very carefully put it all together. I am pretty good with my hands and building little things like this (except for that time I wrecked the battery connector...) so I am relatively sure that it is put together correctly.

SYMPTOMS:

When I plug it in, it gives me the "Please wait. Very low battery" screen, then sometimes it gives me the sad Mac with the apple URL, then other times it says to please go restore it, and then sometimes I'm able to get it into disk mode ("Ok to disconnect", then "do not disconnect") but it doesn't do anything. It's just like this endless parade of personalities. I can't diagnose the problem because every other minute, it's displaying a different error screen!!!

I have gotten iTunes to recognize it intermittently, even to the point of restoring it and uploading some songs, but then it just disappears again. I even reinstalled my old hard drive and am getting pretty much the same story, which tells me that perhaps the original problem wasn't even the hard drive.

As I type this, my computer will not recognize it in any capacity. It's been sitting on the "very low battery screen...." oh! It just popped up Sad Mac. Then went back to low battery. Now it's the apple logo. Now it's low battery. Sigh.

If it was the battery, wouldn't it be working fine except for not holding a charge? I am worried that it's the logic board; either it's defective or that different version really does make a big difference. Maybe because I am using 32gb SD card instead of 30gb spinning hard drive - perhaps the 1763 can't handle that? That means sending it back to China and getting a replacement... a two-month endeavor. Bleah!

At this point, it's not even about saving the iPod. It's more to satisfy my need to know what the !&&* is going on with this thing. I have actually taken the entire thing apart and made sure it was all clean, everything was connected just right, etc, so I don't think it's physical.

ANY thoughts are appreciated. This has been kind of my mental Everest for the last month.