Ok, here's how to fix your phone:
You need a 2 GB or greater microsd
1. Download HTC 8S rom from
here and extract the .exe with 7-Zip
2. Format your sdcard to FAT32
3. Copy file to sdcard and rename it to RIOUDIAG.nbh
4. Put the sdcard in your phone
5. Shutdown phone and boot while pressing camera button. The text RIOUDIAG.nbh should appear and your phone will start flashing.
Do steps 3,4,5 with the files from extracted exe in the following order:
- RUU_signed.nbh
- UEFI_signed.nbh
After that your phone is in original WP8 GDR2 state and should be working again. You can update to GDR3 via phone update.
Hope I helped you!
myst02