can't post comments, pardon the intrusion.
you will most likely have to interrupt the bootloader (put it in ROMMON mode) and flash a new image.
it could be nvram corruption (actually, that would seem to indicate a problem in flash).
see: Cisco - Recover the Image on an ASA 5500 Series Security Appliance (PDF)
or it could just be some control message is being misinterpreted. have you tried a telnet/ssh client? but that kinda looks doubtful.
also, try different (lower) baud rates, could just be some settings on the unit, or erase nvram in rommon.
edit: --
well tbh, i've only dealt with asa devices on 2 occassions. so i just don't know enough about them to say.
i couldn't make any sense of that log file, but looking at it now. it is failing to load the image, at the very end: eadng romflah.. !. rypochcksm (nchnge): f290c46b337a 5f275f 184120
some checksum error
normal output is !!!!!!!!!!!...
spam.
edit2 --
just some more info on erasing flash: erasing/formatting flash should check for/mark bad blocks. additionally, erase marks blocks as 0xFF and reinitializes the filesystem. some of this stuff i just learned today, so bear with me ;p
you can test the filesystem for bad blocks fsck -test flash
. (these are bootloader commands) for a switch, the recovery looks something like format flash
, flash_init
, load_helper
, copy image over, boot system flash:filename
.
as per the following guide: Recovering Catalyst Fixed Configuration Switches from a Corrupted or Missing Image
bootloader cmd ref: Catalyst 2950 and 2955 Switch Boot Loader Commands
image/filesystem ref: Managing Software Images and Working with Configuration Files on Catalyst Switches
for asa 5500 series: ASA 8.x: Troubleshooting ASA Flash Errors
closest i could get for ASA. i always have issues finding detailed guides for them, so i tend to use the switch/router guides as additional info.