After five and a half years, the display on my device has also retired. I'll probably be on the lookout for a replacement device.

No, in this price range, a new purchase might be cheaper.
With mine, the display "changed" after a short time, i.e. it became dimmer at all levels and/or the background 'lit up'. Disconnecting it from the power supply (unplugging it and plugging it back in again after a while) solved the problem for a short time, but it reappeared later.