EIS 4000 problem

I was in northeastern WA this weekend, the temps on the ramp were 90+ and there was no shade to be had, I dont have a canopy cover either so it got pretty hot in the cabin. The tach function in my EIS 4000 went haywire and started indicating real irratic numbers after sitting in the sun for an hour or two, but went back to normal after running up to 10,000' and cooling things off a bit. Has anyone else had similar experiences?
Kevin -8

EIS 4000 Problem

I had the same problem with my EIS 4000 the first summer I had my 6A. We would fly in somewhere for lunch or shopping and the plane would get really hot out in the Texas summer sun.
As we took off the display would become erratic like you described. After climbing to a cooler altitude, it would settle down.
I called Tech Support at Grand Rapids and was told my unit had an older chip in it that had a history of this problem. They told me to pull it out (pretty simple to do) and ship it overnight to them after a weekend of flying and I would have it back, ready to reinstall by the following weekend.
I did as told and they repaired the unit, free of charge, and returned it in plenty of time so I wouldn't miss any action on the weekend.
That was over 14 months ago and I've been absolutely pleased with the display since.