I have tried 8.0, 8.2, 8.3, 8.4 codes. I have also swapped RAM and flash.
Has anyone seen this before?
Have you tried breaking into ROMMON and loading the image Via TFTP? When you do this the image is loaded directly from TFTP into memory, so if that works there may be a problem with the flash.
Also, double check the release notes and make sure your ASA meets the system requirements for the image you are trying to load:
Hope that helps.
Thanks for the reply,
I was also thinking that it could have been related to the flash, so I tried booting from TFTP. This only produced the same result, and it hangs at dosfsck.
All of this still does not explain how it can still boot 7.x code from flash...
Have you tried some maintenance on the unused flash space? I'd have a go at the suggestions here (as applicable).
If that's to no avail, then a fresh download from cisco.com of the ASA software, preferably using a different system than the one you are curently using - both for the download and tftp (or ftp). Since you've said you replaced the CF card, it's looking to be a problem further upstream.