2008 radio-navigation screen doesn't always come on ~50%
 

When I start the H2 for the first time each day, the nav/radio scene usually comes on. Reverse gear shows back up camera picture. Turn off the engine, go into the store come back out start up but nothing on the screen. Radio plays, but no way to change stations to pre-set favorites. After a short period the system may come back on line. These units are GM truck units. I think the replacement cost is about $2k. Anyone else have this problem? Solution ? Ideas?

Thanks
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