Apple iPod Nano 16GB. Purple. Working but issue with screen.

Working but issue with screen makes it difficult to navigate menus. The issue is intermittent, screen will sometimes work but only for a few minutes. The screen itself seems fine when it works (there are no dead pixels or lines) so I suspect there is a deeper fault. Has been restored to factory settings today, iPod was recognised by my MacBook and restored quickly with no issues. Please see the photos for general condition.

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