I have one here with the same problem, it is branded for TIMa dn it stay at the TIM logo when powering up.
I neeed to Full or Custom reset this set, but I dont know what Cable or software uuse for this, I read somewhere z320 cabale would work, but I dont know if USB or Serial, I have serial Z320 cable from my Santel, not the USB one.
I made a search for Z220 on this forum and it returned only 3 posts, nobody has this phone ?
BTW, No software seems to have this phone on the list