Hi, new time EEVblog forum user, but long time watcher here..
I recently got a Yihua 937D+, and the center digit on the display is messed up, I removed and inspected the control board and can't see any obvious faults, dry joints or issues, and wondered if anyone has any ideas

It heats up, and seems to work fine otherwise - the seller gave a 70% refund (they said it would cost more to return and replace, hah)