johng wrote:Jan,
I think there's some misunderstanding here. If you are able to modify the wave shape of both the 0.1 and 3.3 test signals by adjusting C3, this strongly suggests that SENSEL3 isn't being toggled properly.
If this is the case, then the C5/U1A circuit is *not* used at all. Modifying capacitor values wont change that.
John
There may be two questions here. One is whether SENSEL3 works properly in normal operation. The other is whether it works properly during the calibration process. It seems it would almost have to work properly in normal operation, because otherwise high input voltages wouldn't display properly. But as I remember, the calibration process opertes in its own routine, and SENSEL3 might not be working there.
And I guess there's a third question as to whether any of this is different on the new boards and new firmware.