The display on my Audio Analyzer Kit K8098 starts getting vertical lines and other characters after it has been in use for about a half hour, also the text becomes unreadable. It starts with small vertical lines showing up between the bars in the 1/3 Octave display. Eventually just about the whole display is covered with lines and black squares. If I go into the Menu the text is unreadable, just thick black lines. If I remove power and wait a couple minutes it works fine for a much shorter time and the vertical lines start to appear much faster.
I did what another post suggested and put a .1uF capacitor between VCC & ground, didn’t help.
The room is 77 degrees F. The temperature inside the enclosure is 79 degrees F.
The analyzer is installed in a plastic instrument enclosure 2.5 in high x 6 in deep x 8 in wide. I have drilled ventilation holes on the top and bottom of the enclosure directly above and below the analyzer.