Originally Posted by fiberglass1
If you've gone through 4 units served by the same power source then I would be suspicious of the source. Electronics don't like spikes or low voltage.
Have you checked out Garmin's help line via internet? They've been extremely helpful to me and they have a flat fee repair service for non-warranty units. They couldn't fix my 8 year old Fish Finder/GPS unit so they sent me a new one for the price of the repair ($310).
Heck, it would have cost me more than that just to change the hole it came out of (to fit a new, different one) which was a carbon fiber panel!
Hmm good point on the supply voltage. I have run them all on the same power point via the Garmin cigarette lighter cord. I think it is a pretty stable supply as I have 675 amp hours of house battery mostly fed by a solar pack and a separate starter battery. The engine driven alternator has the Balmar regulator which ramps it up slowly.
Does anyone know if the 12 volt Garmin supply lead has built in surge protection?
If not is there a good surge protector around that will last in a marine environment.