See other post on this forum, about it. On power up they will also often just display flickering lines on the screen. It is a problem recognised by Seaward on a number of 350's. We had a batch of 5 units with this feature. Seaward replaced the display module for free, it still occurs but much less often. I can usually nurse it blind to the end and print labels before powering down and up again to clear it.