On Mon, 19 Feb 2007 09:57:04 -0500, RNR
wrote in :

I have owned a 196 for about four years, without any serious concerns.
Last week, I encountered a problem that is serious. While the unit
works fine on aircraft power, it will not function on battery power.
It will turn on but it will shut itself off within 30 seconds. This
happens every time. Has anyone experienced this? Do I have any
chance of rectifying this without sending it back to Garmin? Thanks.
RNR


My experience has been that, should vibration jar the six batteries
sufficiently to momentarily interrupt the power to the unit, it can
cause a malfunction. If the interruption is long enough, the unit
will shut itself off. But, if the power interruption is of shorter
duration, the failure mode is unpredictable.

To overcome the issue of the batteries suffering vibration induced
intermittent contact, I soldered a 0.1, 50v tantalum capacitor across
the power wiring, and haven't had a problem since.

I realize that if you do the math, this fix will only hold the power
up for a very brief time (typical running current is 170 milliamps at
9 volts). But, it works for me; no more trouble since it was
installed.