Ok, so I swapped out the main board and several problems went away. I am now getting a signal on channel 1, it is now accepting a change in column diameter and some minor pressure problems we were experiencing have gone away. I was never able to independently verify the detector temp, but adding a moisture trap on the H2 line eliminated the moisture in the detector. I think I got a bad tank in that regard. Now I can get back to attempting quantification on PDMS. Thanks for all of the help!