[time-nuts] 2100f lcd display

Chuck Harris cfharris at erols.com
Wed Apr 20 15:11:02 EDT 2005

I hate to reply to myself, but there is another failure that will cause
the LCD display to go nutty, if the +5V logic supply is not regulating
properly, and is up around 5.5V, the display will do just what you are


Chuck Harris wrote:
> Hi George,
> There are two problems with the 2100 families front panel.  The LCD,
> and the keybuttons.  The keybuttons were not properly debounced for the
> long haul.  As the switches get older, the bounce time increases and the
> keypad logic starts to generate multiple switch entries for each press.
> The fix is to replace the two 1uf tantalum caps on the front panel (C5 
> and C2) with
> good quality 2-5uf tantalum caps (ceramic would be better).

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