I did see those jumpers when I opened up mine to check capacitor/etc when mine bricked from upgrading FW. Which jumper(s) did you disconnect? JP14 or JP15 or both jumpers in that picture. Also, was there a change log for the latest RCA Security app? I haven't used the RCA app since initial setup back in Jan as Ezviz and Hik's app were better in my mind at that time. I have LED front porch light that is auto-on/off at dusk/dawn so IR stays off but this manual disconnect power leads workaround should work.
are you sure yours was bricked??? use ivms-4200 or web GUI to log in and then hit reboot. don't use the app to try to log in. after rebooting using ivms4200 or web gui, use phone app to add it manually using serial number and verification code. i always do it like that without any problem