Whilst recently travelling back to Queensland from Victoria on a nice sunny day, we pulled over for a rest break at a road side stop. Upon resuming our trip, the faithful Garmin failed to restart when the ignition was turned on. Checked fuses etc and noted that the back of the unit seemed to be excessively hot. Removed it from the windscreen mount and left it in the shade for the rest of the day and the following day it fired up as normal.
Has anyone else experienced this ? (The Garmin 320 that this unit replaced had been all over Cape York and extensively through the NT without any similar problems) More importantly, any suggestions about how to remedy the probably over-heating problem will be greatly appreciated.
My 760 had the same problem. I was travelling in the southern part of Victoria and we stopped for lunch. When we resumed our journey the 760 wouldn't start. Tried a soft reset but to no avail. Left the unit off for 3 hours whilst driving to Sale and then tried to turn it on (to find a motel) and it started and worked fine. Haven't had a repeat since, although in the last week the 760 freezes whilst in navigation mode (seems ok with just the map on). The only way to fix it is to turn it off and then back on again. Hopefully this is not a sign of the unit deteriorating.
When my unit failed (like yours) it was also very hot and the only way I can keep it cool (as my unit sits on top of the dash not the windscreen) is to put the a/c on demist. This blows cold air over the windscreen and dash.
Never ever turn the ignition ON (and start the engine) while the unit is plugged into the cigarette lighter socket as some systems may draw far too much power from 'whatever' source they can.
This excessive draw of power may permanently damage old and weak Li-Io battery in your Garmin and the unit itself.
Always disconnect your Garmin from the cigarette lighter when you turn the ignition OFF.
Suspect that there may be a temp sensor thermistor internally to protect PC Board from damage, thus cutting unit out until temp drops to a safe level. Have seen it in many electronic devices.
There are warnings in the instruction/warranty re max and min temps.
I've had the same problem with GPS and phones mounted near the windscreen and have found that keeping the aircon on is about the only way to address as moving the units just makes it too hard to view them