[Galaxy Note 3 Q&A, Help & Troubleshooting] bearcat81:
Hello all,

I've read and searched through a few posts before posting this, and it seems there has not been one consistent solution offered that is a guaranteed fix. And no problems that have been solved like this in the past 6 months or more that I saw.

About 10 days ago my Note 3 started doing all kinds of crazy crap. It would:

Boot up with a yellow exclamation point and says Verizon Wireless had detected unauthorized software on my device. In the top corner it would say secure fail: modem. This almost always went away with just another reboot of the phone.

Boot up with a splash screen that normally just says Samsung Galaxy Note 3, but now also has an unlocked padlock and "Custom" on the screen.

Extremely intermittently recognize that I had a sim in my phone and provision my phone on the 4g network.

Not allowi a significant amount of internet activity even when connected to wifi.

Pop up an error box upon entering the OS saying that there was a process system error and ask me to wait or kill the process.

Random unrequested reboots of my phone without even touching it. (this has happened 7 times now through the course of typing this post)

Also a problem, though not a recent development, is a common complaint that there has been significant difficulty in placing clear phone calls even though signal strength looks good, sometimes resulting in attempts to dial timing out without making a connection.

As a bit of background: I've never rooted this phone. Years ago I sold smartphones for a living and I knew how much of bastards Verizon et. al. were when it came to providing hardware warranty coverage to people who had rooted their devices. Having said that, I have no idea why I just randomly started seeing an unlocked padlock and a callout for a custom OS on the boot up splash screen. Also, I've already gone to verizon and replaced the sim just in case it was a defective chip causing these problems. There have been no significant changes, though it does seem that the intermittent rate at which the phone actually finds the network happens a little more often with a new sim. Maybe that's just my wishful thinking that my situation has improved.

Other things I've tried for troubleshooting already:

Booted into recovery mode, wiped cache, rebooted.

Booted into recovery mode, wiped and factory reset the phone from the on board restore software.

Downloaded Kies and booted into download mode on the device and pushed the current OS image to my phone.

Tried some silly battery trick that some guy made a youtube video about where he suggests pulling the battery, pressing the power button for a few seconds, then putting the battery back in will fix the problem.

This phone is out of warranty now, so I'm not opposed to trying a rooting solution to fix it -- if that is even plausible. I also downloaded a 1.6GB zip that is supposed to contain an image of the LP OS (N900VVRUEOF1_N900VVZWEOF1_VZW.zip), but have not done anything with it yet. My only concern with trying to wipe out the stock OS is that I've never attempted it before and don't want to F it up, although at this point could it get much worse??

Cosmetically this phone is in perfect condition. I'm not a phone dropper, and it has been in an otterbox defender case since the day I got it. I bought this phone outright in 2013 so that I could preserve my unlimited data plan, so I'm really hoping there is a potential solution here that does not involve buying a new phone.

Any suggestions you can offer would be great. Like I said, I did some keyword searching on this form and read a few threads before posting, but it seemed like there were a bunch of different theories on how to fix this problem and no consistent solution.

Thanks!