Well, for as long as you see the SONY ERICSSON boot logo - and I'm assuming from the way the X8 works here - the boot loader and kernel are intact; there's just a problem boot-strapping the system ROM (shot system, bad flash).
The real problem is that Fastboot isn't comparable to the Flash Mode of our phones ... it's very different.
In your stead I would try to find out how you can perform a "disaster restore" (like we do with our W/X8 through Flash Mode and Flashtool) by flashing back to stock.
Anyway ... just to repeat it ...
1. You need to TURN OFF your phone and DISCONNECT it from the computer/charger.
2. You insert the USB connector into JUST your phone.
3. You press the bottom/right button (also "Back"?) and keep it pressed while you connect the USB to the computer.
Once the phone connected to the computer as a (wild guess!) "Flash Device" or "Fastboot Device" you need the apropriate tool(s) and Stock ROM image - in case PC Companion refuses to repair your phone.
---------- Post added at 12:21 PM ---------- Previous post was at 12:18 PM ----------
Any chance
this thread (in the Xperia Neo General section) could be of any help to you?
Thanks! I tried like 50 times, and nothing, the ennoing "sony ericsson" is booting (no sony ericsson logo as usualy, just the writing) I flashed 10 times in the past whith no problem. Now, even when I put it to charge ( wall charge) the phone is turning on showing that stupid "sony ericsson" writting, I cant shut it down from the on\off button. Before killling it, I've instales stock MT15i_4.0.A.2.368_GLOBAL ROM, then I upgraded to MT15i_4.0.2.A.0.42_Global, then rooted with DooMLoRD_v4_ROOT-zergRush-busybox-su, Installed CWM( wiped cache, updated SE tweaked v8.5 Rom) After the restart, the "se" writting started booting. I've pulled out the batery, and begined flashing it with flash tool(no green led).The flashing started and my little brother accidentaly pulled out the Usb cable; that's the whole story! I've tried like 100 times with wotan, flash tool and FlashTool_0.2.9.1_FOTAUnbrick, no result, even if pc companion tells me "phone conected" and gives me further instructions whith the phone being dead, and the flash tool showing me to connect de device... Thank you for all the help, hope there is a solution. sorry for the long post and my bad english...
---------- Post added at 11:43 PM ---------- Previous post was at 11:24 PM ----------
04/040/2012 23:40:02 - INFO - For 2011 devices line, be sure you are not in MTP mode
04/040/2012 23:40:04 - INFO - Device disconnected
04/040/2012 23:40:06 - INFO - Device connected with USB debugging off
04/040/2012 23:40:06 - INFO - For 2011 devices line, be sure you are not in MTP mode
04/040/2012 23:40:07 - INFO - Device disconnected
04/040/2012 23:40:10 - INFO - Device connected with USB debugging off
04/040/2012 23:40:10 - INFO - For 2011 devices line, be sure you are not in MTP mode
04/040/2012 23:40:18 - INFO - Device disconnected
04/040/2012 23:40:35 - INFO - Device connected with USB debugging off
04/040/2012 23:40:35 - INFO - For 2011 devices line, be sure you are not in MTP mode
Flash tooll results when trying to connect (pulling batery-10 secs, back butoon, usb cable)