so I recently got a friend broken 5D Mkii. the problem is the second i insert the LP-E6N battery it jumps to life and goes into the firmware update firmware and when i attempt to update it, it goes to 99% or sometimes 23% and pops up "Update file error. Please check the memory card and reload the battery and try again." i can't access the menu or anything, im stuck in it and i tried everything. my friend never used magic lantern but i been on other forums and asked canon collectives, etc and im at a lost. i tried everything to different CF cards/batterys to pulling the thing apart to see if something was lose or missing on the logic board. i tried looking for older firmwares since the original firmware is 1.0.7 trying to update to firmware 2.1.2 but i had no luck in finding anything. i even tried putting magic lantern on it even tho the firmware isn't 2.1.2 but i got one flash on the LED and a black screen. im at the point thinking it's a logic board issue or something. please help, thank you in advance