On Fri, 03 Jan 2014 21:11:03 -0500, Donald
wrote:

If there is an internal memory cell battery, you might disconnect
power from it by removing it for 10 minutes then reinstalling it to
see if that resets it.

I found some information on modding it. Maybe going through these
keypresses might shock it back to normal?
(snip)

And how may that help the O/P who has a C510?