I have a 788 CI that's somewhere around 5 years old. Maybe even 6 years.
And this problem has existed for almost the entire life of the unit, so I should have addressed it a long time ago, but never did because I didn't want to be without it.
Anyway, I've had trouble with it acting up when it gets hot. Once it reaches a certain temperature, the screen goes a whitish gray color. And then it gets funny multicolored vertical lines on the screen and stays that way.
None of the buttons will work at that point, so the only way to power it down is to remove it from the mount.
If I let it sit for a while and then power it back on, it will work for a short while and then do the same thing again.
I don't usually have much trouble like this, since I fish at night during the summer months, but it happened to me yesterday during our club tourney. Skies were mostly sunny and temps were in the low to mid 80s.
I will be calling Humminbird tomorrow to ask them about it, but I'm sure they'll tell me to send the unit in. Was just wondering if anyone else has had any similar problems with their birds.