I have the LMH5401EVM and I am in the process of evaluating this board. I connected it and powered using the single supply and manually grounded the PD pin. Still, I am unable to see the amplified signal. It seems that the amplifies is disabled by default. But, if I use the LHM5401 chip on my own proto board with the supporting circuit, which is not much different than the EVB schematic, I get the desired output. Is there anything different that we need to do in the EVM?