[time-nuts] Austron 2100 keypad?

Chuck Harris cfharris at erols.com
Tue Jul 22 14:07:42 EDT 2008


Hi Dan,

It is a very well known problem.  As the key contacts age and get dirty,
they sort of "fry" rather than make a clean contact.

You can gain a short term fix by replacing the two 1uf tantalum key debounce
caps with a larger value.  These capacitors are axial leaded hermetically sealed
wet slug types.  They are the only two on the front panel board.  Their
designation is C2 and C5, and they are located right next to the 74C923 keyboard
debounce/encoder IC's on the front panel printed circuit board.

I have replaced them with 3uf to get a mild improvement, 10uf seems to be a
pretty good balance between key press response, and debouncing.

Eventually, you will need to replace the keypad switches.  They are individually
soldered onto the board, and should be available.

-Chuck Harris

Dan Rae wrote:
> My 2100 timing receiver (no suffix) has started to give me problems with 
> what looks like bounce from the keypad switches, with a lot of numbers 
> repeating without being asked.  Is this a known problem with these 
> units, and is there a known fix?  I don't think the guts of the pad are 
> accessible for cleaning.
> 
> Thanks,
> 
> Dan
> 
> 
> 
> 
> _______________________________________________
> time-nuts mailing list -- time-nuts at febo.com
> To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
> and follow the instructions there.
> 



More information about the time-nuts mailing list