Hi all,
New here
I did search but couldn't find anything similar.
My 3590 has black marks, generally looking like grey texta/felt tip pen marks, a block of them say; 9 lines in parallel, then normal map, another block with different grey lines. These can be different each time I restart.
I can scroll around and the marks/blocks move with the map.
I have tried restarting (not full reset). Changed most of the menu options, still with other styles the marks remain, maps are up-to-date, so is the software.
It does correctly navigate.
Any thoughts gratefully received.

I will try to upload a pic.
Thanks, Paul
New here
My 3590 has black marks, generally looking like grey texta/felt tip pen marks, a block of them say; 9 lines in parallel, then normal map, another block with different grey lines. These can be different each time I restart.
I can scroll around and the marks/blocks move with the map.
I have tried restarting (not full reset). Changed most of the menu options, still with other styles the marks remain, maps are up-to-date, so is the software.
It does correctly navigate.
Any thoughts gratefully received.
I will try to upload a pic.
Thanks, Paul