Posts: 472
Threads: 58
Joined: Apr 2008
Posts: 4,027
Threads: 172
Joined: Aug 2005
Hi;
I've heard in on mine, too (No mice, Doc.. no mice!), at lest twice, and it seems there is a drift in an oscilator. When it happened with my HP41CV, I rebuilt it after more than ten years spread appart inside a shoes' box, and it sqweeked, too. I turned it upside down and left to right and the tone changed (high-frequency with a low-frequency component). I remove and replaced the batteries: a quick tone, a [MEMORY LOST] and the life goes on...
Cheers.