I built one of these cards but I am running into an issue where the LM3940 is outputting just over 1.5v, instead of 3.3v. As such the board is not working.
It seems to expect a decoupling cap on the input, and polarized cap on the output. However let's look at the application of this regulator in the design I'm using/building, shown bottom right:
C4 is a polarized 10uf cap on the input, and the output doesn't seem to have a capacitor present.
I have already desoldered and replaced both the regulator and capacitor, and with another regulator, I'm getting the exact same voltage.Should I be looking to add a cap to the 3.3v output, a different cap on VCC input, or both? Surely I can't have 2 identically faulty voltage regulators? 5V tests great going into the card. Photo for reference though it should be all but identical to the one on the github for the project https://github.com/retrotink/Apple-II-VGA