[Captivate Q&A, Help & Troubleshooting] HoberShort:
About two weeks ago, I installed the teamhacksung ICS ROM. Three or four days later, I pulled my phone out of my pocket to see it doing what looked like the boot animation (the rainbow of cards flipping over in a circle) at a very, very dim brightness. I let it run for a few minutes before battery-pulling. It came back with a screen saying "Encryption unsuccessful", saying I've lost the data on my phone. Hitting the reset button on-screen would reboot to a black screen and hang.

Alright, whatever. I'll reflash my rom or go to a Nandroid backup.

Except when I get in to CWM, it can't mount my sdcard ("Error: can't mount /sdcard/") and I can't mount it on my computer. I can flash all manner of ROMs via Odin/Heimdall, but none of them can mount the sdcard (also sometimes seen as "Can't mount /dev/block/mmcblk0p1 (File exists)" in recovery) and therefore can't boot.

None of the stock ROMs will boot (I assume because they can't find /sdcard and /data). Running KB2 with the Onix kernel added, I can boot and get a phone with no storage space, system, internal or external (with external SD card inserted).

I can get in with adb shell and poke around. There is no /dev/block/mmcblk0 device, much less partition 1 (p1) on it. There is /dev/block/stl1 through stl13, which seems to be where the phone is running off of. Result of running mount:

# mount
mount
rootfs / rootfs rw,relatime 0 0
none /acct cgroup rw,relatime,cpuacct 0 0
proc /proc proc rw,relatime 0 0
sys /sys sysfs rw,relatime 0 0
tmpfs /tmp tmpfs rw,relatime 0 0
/dev/block/stl6 /mnt/.lfs j4fs rw,relatime 0 0
/dev/block/stl9 /system rfs ro,relatime,vfat,log_off,check=no,gid/uid/rwx,iochar
set=utf8 0 0
/dev/block/stl10 /dbdata rfs rw,nosuid,nodev,noatime,vfat,llw,check=no,gid/uid/r
wx,iocharset=utf8 0 0
/dev/block/stl11 /cache rfs rw,nosuid,nodev,noatime,vfat,llw,check=no,gid/uid/rw
x,iocharset=utf8 0 0
tmpfs /dev tmpfs rw,relatime,mode=755 0 0
devpts /dev/pts devpts rw,relatime,mode=600 0 0
tmpfs /mnt/asec tmpfs rw,relatime,mode=755,gid=1000 0 0
none /dev/cpuctl cgroup rw,relatime,cpu 0 0
/dev/block/stl3 /efs rfs rw,nosuid,nodev,relatime,vfat,llw,check=no,gid/uid/rwx,
iocharset=utf8 0 0

Notice no mounts for /sdcard or /data . I also have compared `mount` before and after inserting the sdcard, and `ls -r /dev` to see if anything changed when I inserted it, and there's no difference. In the SD card screen in options, internal and external sd card show as unavailable, as does the system space.

So, I'm not sure if that encryption unsuccessful message was just a misdiagnosis or true (I didn't tell it to do any encryption).

I have flashed a dozen different ROMs with Odin, and they all either do this (or don't boot, I assume because they can't handle not having /data). This isn't a ROM problem. I ended up flashing a lot when I was installing the ICS ROM (I screwed up), so my current working theory is that doing all that put a lot of wear on the internal sd card, which failed shortly thereafter.

I'd be okay with doing a switcheroo to make the phone see the external sd card as the internal and running that way (like a normal Android phone), but like I said above, inserting the external SD card doesn't register any change in the OS.

At this point, I'm out of ideas.