My Heathkit H8 did not work correctly when i received it. I noticed that many chips had oxidized pins, so I spent some good hours cleaning the pins and “deoxiting” the sockets. It actually worked fine for a few days. Today when I fired it up, it acted really weird: there were missing segments on the LEDs, and after a few seconds, the display went to a single digit. I shot a video and I would really appreciate it if anyone can share some idea here.