Can you still boot into bootloader? If so, you can try this:
Download an RUU
1. You now need to pick the RUU you wish to flash, a good source is this thread:
2. Once you have downloaded the RUU you would like to flash, run it (it can take a while to load), and stop when you get the welcome screen, which has a picture of a Sensation on the left and a red caution notice on the right.
3. Move this window out of the way (it forces itself into foreground), then open up windows explorer and go to:
4. Then sort by Date Modified. Find the newest folder with a long random sequence of numbers as its name, go in here and you should see, three files and a folder: corecomp, dotnetinstaller, IBSEW64. (the files may be different on 32-bit OS), now go into the folder which has another long random name.
In there amongst a lot of files (use search if you need to), you will find rom.zip. This is the rom we want to flash!
5. Copy the rom.zip file to the root of your SD Card
(i.e. if your on Windows, X:/ [where X is the letter of your Sensation's SD Card])
6. Rename the rom.zip you just put on your SD Card, to PG58IMG.zip (ensure you do not rename it to PG58IMG.zip.zip or it wont work!)
7. Find the "HTC Android ROM Update Utility" Window, and hit Cancel.
from my HTC Sensation using XDA