I'm troubleshooting an old (1995) LeCroy scope that has shown some irregular behavior lately ("multiple calibration errors" warnings, display freezes for a while when changing the volt/div and time/div settings, etc), especially after running for a while. I won't bother you with all that—I'm just wondering if the cap in the picture is damaged? The picture quality is not great, but it's the best I could do. I thought it looked worse in a 4X microscope where the bump seemed darker/grey/black in the middle. Any thoughts?