HP 35 display

[Thomas Puettmann]

I just noticed something in complete darkness, see picture.     You have to enlarge the picture to see it. Could this dimly shining dot be related to the not glowing segment?

The calculator is from my late father. In his company Graetz (Radio + TV, later acquired by ITT) they bought many HP 35 and attached them with chains to the desks. (Does this make sense for pocket calcs?). Some years later the employees were allowed to take them home. Must have been around 1976 when I was 8 years old. I was very happy to see a pocket calculator for the first time. The batteries were already not working properly at that point of time and so the machine went to the drawer. Only some months ago, I put some 3.8 V drone lithium polymer drone battery inside and recognized the segment error. Unfortunately, because, otherwise, the LEDs are a pure joy to look at.