Found these inside a non-working 71B

[MikeSD]

This is puzzling. I'm still thinking the RAM might be ok and there is a connection issue. But since the 71B that this was in, is now working, I'm going to spend only a little more time in the test unit. If I can't figure out the problem, I'm going to put it back where it was in the original 71B.

Results later.