My mah7500 tries to spin but fails to go into high speed. when I access the diagnostic screens and do an unloaded spin test, it shows an imbalance value of up to 200 or so at speeds up to 300 RPM, then zeroes out when it goes faster with no load. It will spin to 1000 rpm smoothly.
It doesn't throw an imbalance code during the cycle - the only stored codes showing on the diagnostic screen are "7" - heater failure, which I'll deal with as a separate issue)
The only explanation of plaster detection I could find is in Maytag's patent number US6594841 (you can see it on Google's patent site) where it describes looking for erratic torque as it runs the drum slowly. My drum isn't noisy, but I don't see what this could be other than bad bearings. I haven't pulled the unit out to hand-rotate the drum and feel the bearing for myself. what is my next step?
If it is bearings, I've read that the official fix is a new basket / drum, while there are some web sites that talk about replacing the bearings themselves. recommendations?