Here’s my guess.
Someone was testing/ touching the displays...display wasn’t in the bracket all the way and it popped out and shorted to the metal housing on the solder side of the pcb.
I only say this because this happened to me haha
I was told that section of the mpu probably ate shit but I ended up just replacing the mpu. Still have the old mpu on a shelf, haven’t gotten around trying to fix it.