I tried to clean the board (the side with LCD) but to no avail. Really strange is that letters/numbers are better visible when I change radio to AM, FM or playing tape they are dim. I'm using gum batyery and even added AA battery compartment but it's still the same. It's quite annoying and it's hard to use especially FM radio. I would apreciate any help.
A common problem with LCDs is bad connection through what they call a "zebra strip". https://www.electronicspoint.com/forums/threads/can-you-fix-a-zebra-strip.256566/ The displays have lots of common connections so a bad connection on one segment can affect others, in the same way that a bad earth on one car bulb holder can affect a whole set of lights.
Funny thing that when I went outside with bright sun it was visible under some angles very good. And surely better in 90° angle than at room with not so bright artificial light. I think nothing is missing then, and contact is quite ok.
Greetings there can't remember exactly this model but could you please tell me is there a ribbon connector Uniting the lid to the main body