Experienced flasher, soft-bricked my Note 4 real good.

Hi guys and gals.

I've been flashing roms for years and I've soft bricked my devices dozens of times and have always been able to recover, except this time.

I was running Cyanogen mod 12.1 and all the problems started happening after a nightly update. Basically, the phone got super laggy and eventually started random rebooting. I thought it was a bad flash or something was wrong with the latest update so I did a clean wipe and flashed another rom, same thing happened. Eventually I Odined back to stock and it ran fine for a few days but the problems came back. Now the phone won't even finish boot anymore. I used NAND erase all in odin and and reflashed again, it seems to be better since it wont reboot its self anymore but I can't get past the T-mobile splash screen. Last night I tried reformating the NAND using a PIT file but I kept getting "Secure check fail : PIT". I was starting to thing the problem is hardware related but it won't RR in download mode and I think its too big of a coincidence that it happened after the Cyanogen update. Any ideas?