February 11th, 2013, 06:12 PM
Join Date: Jul 2012
Device(s): Google Nexus 5
Rom: Cataclysm 4.4
Recovery: TWRP 2.6
Retired: HTC Evo 4G, HTC Evo 3D
Thanked 4,429 Times in 2,503 Posts
Hmmm.. If an RUU exists of the ICS update, you should at least be able to update that way. You would be stock and unrooted but on ICS. Then you can just root again.
I don't have a thunderbolt, so I don't really have an arsenal of resources for you. But poke around here:
It looks like at the bottom, they have ICS available. Make sure it's correct for your phone. I just did a quick search on your phone to find out it's alias, hopefully mecha was correct. But check the filenames and make sure it has all the right info for your phone.
Edit: I don't like how there are two of the same with two different MD5 sums... Not sure which one I'd go with. Might wait for another thunderbolt user to throw in their two cents...
Last edited by Brian706; February 11th, 2013 at 06:14 PM.