Google 'AM2901 bitslice tester'.
However none of those solutions will be as easy as just taking a known-working boardset, and swapping them in one by one, then booting into test mode (i.e., power up with the test switch already flipped on). If they're bad, self-test will indicate a mathbox error. ('M' for Tempest, or T, H, or L, for Battlezone.) I use a Tempest boardset to test them.
The four 2901's work together as the mathbox, and any one or more of them being will throw a mathbox error. So there's no simple way to map specific game behavior to a bad 2901. You usually will just get very messed up graphics (or no graphics at all) when any of them are bad, because the 3D vectors won't be computed properly.
And that said, you shouldn't run a board with a bad 2901 outside of test mode, as it'll want to draw vectors off the edge of the screen, which isn't good for the monitor. However booting directly into self-test is safe, because self-test doesn't draw any 3D graphics, but will still report mathbox errors if anything is bad.