I was a timber yard supervisor
I had the classic 3210 for years. From time to time when the screen became illegible from dust... Took front and back covers off, blew/wiped masses of dust off the business bit, washed other bits and dried under the hand drier, put back together, sorted!
It was a mosh pit at the Brixton Academy that finally put it on its death bed and even then it clung on slowly losing functions for a week or so. In the final hours just defaulting to a simple tone and unable to display the caller, just "call". Freeky!