PCI-6221 analog input voltage wrong above 5V

[Bill I.]

This is a by-the-way.  Currently I am using just one PCI-6221 and the PCI-GPIB card.  I pulled the othe two and tested them one at a time.  The number of cards has no effect on the symptoms.

[Kilometers]

If your cards are working properly in a different computer then it is almost certainly a problem with your current computer. As for whether an under voltage could cause your issues I'd need to have a better idea of what exactly your issue is. Could you post a larger version of the graph in your original post? I can't read the axes labels or the numbers on it at that resolution. 

Thanks

[Bill I.]

Here's the graph in a larger version.  The horizontal axis could as easily be the 0-10V input signal.  A closer look at the peak values shows that the test panel tracks until the input voltage reaches right about 5.3V.  I pretty much have set on the course of getting a new motherboard, but I'm trying to understand these symptoms for future reference.

[Craig_]

That graph looks like it goes up to 7V, where does it indicate a cutoff at 5.3V?

Also, what voltage range are you selecting for the analog input voltage task in the test panel?

[Bill I.]

5.3V is where the voltage reading begins to deviate from the input voltage, but only slightly.  Then somewhere around 6.5V the deviation becomes extreme.  The max and min voltage settings are set to +10 V and -10V respectively.  My next step is to trade out computers.  I'll let ya'all know what I find.