Also Lost phone with updates
Thanks for all of the info. I attempted this fix on my phone too, but it seems that the battery won't charge once the phone is damaged with the update.
I also got the "M" logo only once the update installed. I knew the screen was on constantly, so I made sure it was plugged in to charge at all times. I downloaded each of the files suggested above, but now that it has been nearly 24-hours since the damage occurred, my phone says I don't have enough battery power to program. I attempted to charge it up more, for the last couple of hours, to no avail, like it's not charging, only applying power to the phone to display the logo. There is no way to shut the phone off once it is in that mode, without removing the battery, and then charging definitely won't happen. I guess I will just wait until I receive my new phone tomorrow.
The phone was damaged yesterday evening with the update, and I went in to the store to attempt a fix this morning. Verizon gave me $15 off my bill for the trouble, and shipped the replacement over-night. Big deal. I needed the thing tonight.
Thanks for all of your help.