I buyed a htc one m7. Its inner hardware is untouched, the rom is stock 4.3.
It was never rooted or something.
It stucks in a bootloop, vol-down+power for recovery does work, I can do a hard recovery reset, but it doesnt solve the error.
sometimes it starts the rom after 30 minutes bootloop, but not often. Now it does bootloop for 3 hours.
No warranty because no copy of the invoice.