On Jun 23, 5:14*pm, "Roy Clark, \"B6\"" wrote:
Have been content with my GPS-Nav Model 20 & L-Nav System (was upgrade
from an early EW) until my L-Nav began to act up. *It is now totally
kaput.

I've had a couple of threads on a similar topic. And, in my case, CAI
looked at one of the acting up units (I have two, because I bought a
used one since CAI wasn't repairing LNAV's after the first problem)
and found nothing wrong. The advice I've received so far:

1. Make sure the power connections are good. Hard to tell, so it might
pay to just redo them. A problem in the power line can cause erratic
readings and behavior.

2. Make sure there are ferrite RFI blocks.

3. Make sure the backup battery is good. The LNAV is supposed to
report when the voltage drops to 2.2 volts, but it might not hurt to
check the voltage and to clean the contacts on all sides. If you have
a logger, be particularly careful to keep 12 volts on the unit while
the battery is out or it may ruin it! In any event, write down all
your settings to play safe.

Hope this is of some help.

Martin