All black meaning no exposure?
1st thing: Did you load the film correctly? I assume that the Maxxum should already have an auto-loading system, right?
2nd: Are you certain the camera works? My first assumption would be forgetting the lens cap on, but you're using an SLR and not a rangefinder so that would be nearly impossible, so I'm wondering if the cam is in working condition to begin with.
3rd: Did you set the ASA/DIN rating correctly?
4th: Using fresh or expired film?
If what you meant my "washed out" meaning your PRINTS came out as white and the negs as all-black, could you have opened the film back accidentally and exposed your neg?
Kinda strange coz you mentioned 2 rolls with 2 different cams but got the same results so I'm dismissing gear error...
I too had an "accident" last week when I forgot to set my ASA down from 400 to 200 in my Konica C35V (being a full-auto cam), I forgot that I loaded 200 film (expired as well, so it loses almost a stop more) and left the ASA setting to 400, which resulted to severely (2-3EV) underexposed shots... But they're not completely gone as bright skies still exposed somewhat, unlike a pure black in your case.
