As said your problem (whatever it is) seems like being NOT a BSY or a LBA0 (but you haven't provided yet ANY meaningful detail/info to confirm or deny this hypothesis) jaclaz I have two similar hdd one that works and the other does not. When I connect the hdd that works with the screw pcb hyperterminal communication with hyperterminal is perfect, when I separate the pcb, this is not connected to the terminal. In the case of the failed disk I can not get connected to hyperterminal in any way. Always using the same ttl converter. Because I can not ge achieve connection with the hyperterminal. Apologize because my English is very bad. http://www.ebay.com/itm/280748167812?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1497.l2649 I want to know why the pcb is not connected to the terminal without being bolted to the hdd. From already thank you very much and sorry for my ignorance