Ok, so here it is. This is a 4Gb SD card image pulled from an Amplifi75 running firmware 2.60. USE AT YOUR OWN RISK!!
So here is what you should know:
-I used the Mac SD image tool, Apple Pi-Baker, to read/write the image with no issues whatsoever. Pretty simple to use. I'm sure that tools like Etcher or Win32DiskImager will work on the Windows side. Not going to get into all that. Any SD tool that can work with .img files should be ok. I replaced 4 cards for all of my amps and all copies worked.
-4Gb SD cards are no longer available at my local MicroCenter. I had to settle for 16Gb MicroCenter branded cards. At $2.99 ea, why not. I've used these cards in a lot of Pi projects with no problems. Rock solid. But this is a 4Gb image, so yeah, after imaging the 16Gb card, 12Gb is left on the table. It wasn't a problem. But don't expect an upgrade to the amp for using a larger card. On that note, make sure you use at least a 4Gb. 2Gb cards will obviously not work.
-Current Firmware- I did run into trouble on the two amps I had not opened yet. They were fresh from the box and still running 1.00 firmware. They would not boot from this image. I had to upgrade them to 2.60 first, and then they worked fine with the replacement SD card. Had I been smarter about it, I would have captured an image from the 1.00 SD card before upgrading. That is my fault. So my guess is that you might need to be on at least firmware 2 for this to work. But 2.60 is all I can confirm.
Here is a Gogle Drive link to the file. Hopefully it holds up. If not, I'll have to find somewhere else to host it. I also hope I do not get asked to pull it. The file is only of use to us with Line 6 amps having problems.
https://drive.google.com/open?id=10ZX7Atp0thGuqxMgiMuEdkTkebOK44Ig