kindle fire hd7 no boot

[ryn0909]

i have a kindle fire hd 7 (i believe its 2nd gen) model# on back cover says x43z60. Messing around with unlocking software, i attempted to unlock bootloader and when it rebooted, the screen went black (as expected) but then it never came back on. its not being recognized in device manager. nothing comes up on the kindle screen. it appears to be completely bricked. upon searching for solutions online, i ended up purchasing usb microB breakout board to build my own "factory fastboot cable". after following the directions for using it, i still have NOTHING. lol so i took the back cover off, disconnected the battery for a couple hours, plugged it back in and still nothing. i have also tried holding power button down for 20seconds, 30 seconds etc... and nothing. then i noticed on the mainboard some writing that peaked my interest, thinking it may help with unbricking this device. see attached picture