Wow...what a mystery! Something is definitely funky. Here's what happened. So I unpacked and converted all your images to the size of my test phone which is 320 x 480. I created the zip file with the retro animation in part0 and the XPERIA animation in part1. I have other animations that are in multiple folders and they all work perfectly. In this case, my phone did not play part1. But I did not get a black screen. It just got stuck on the last image in the part0 folder. My reaction can be described in 3 letters - WTF?
THEN MY PHONE THREW AN ERROR MESSAGE WHICH I'VE NEVER SEEN BEFORE. So this may be a clue. The message said: "Update time failed, please try again later." The phone eventually booted to the home screen as normal.
So I got to thinking. Perhaps your frame-rate was way too slow. So I changed it to 30 frames per second. Same result! Stuck on last image in the part0 folder. But then there was another clue. It got to that 85th image like a rocket and before the boot music could finish. Well what ever is happening in the background to throw this error also stopped THE BOOT MUSIC dead in it's tracks. That is really freaking amazing, So my conclusion is that somehow, something is making the boot animation process "believe" it is done. But it ain't.
Then I figured that perhaps the problem was that the images in part1 were not following the numbering sequence of the images in part0 as the numbering sequence started over again at 0. So I renumbered all the images in part1 starting with 85. But again, same damn result! It simply refused to play the second folder.
So then I had to prove that it was not something funky with the last image of the part0 or the first image in part1. So I moved all the images to a single folder and VIOLÁ, it played the whole thing. Thus proving that there is no problem with the images themselves. But of course, this is not the solution because you want the XPERIA images to repeat and not just play once. So how to make the second folder play?
I tried another tweak. I thought, since the frame rate is 30 per second which means part0 is gonna be done in under 3 seconds flat, what if I change the number of times to repeat from 1 to say 3 or 4? Same result! It plays just once and refuses to play the second folder.
So stupid me, I'm thinking, maybe there is a limit to how many images can be in a single folder if there is a follow on folder. I only guessed at this because the STOCK boot image for Alcatel phones of this type has even more images than your animation and they are in 6 folders! One of those folders had 58 images, but none had 85. So my last step was to split your images into 3 folders -essentially, took your part0 and split it into two (part0 and part1), and the final was part2 with the XPEDIA animation which was to repeat. You won't believe this, but it refused to go past the first folder! So same result!!!
So back to the ERROR message. I began to look into it further. Obviously, after it gets past the very first folder, it is trying to update something. But what? And why does it fail. So I started looking at the OWNERSHIP of the bootanimation. I'm using Root Browser. I can set the permissions of the file equal to those of every other bootnaimation zip that is inside my /system/media folder. I set the owner of the file to 0:Root. But for some reason, I cannot change the owner of the group to 0:Root like the stock file and my other bootanimation files. The group owner stays at 1015:sdcard_rw. That's the only "invisible" difference between this boot animation zip and all the others I am using. I'm also not sure if this ownership thing has anything to do with the problem.
Now, what I cannot figure out is what on earth is it about this file that would be any different than all my other files??? I'm now also totally stumped by something that should be so simple. I've done this so many times before. It must be something so simple we are just missing it. I'll keep trying (I have one final idea to test...will lt you know how it goes).