Twitter is not the easiest platform in the world for reading long content, but at least you don't need to log in if you don't want to. Anyway, the @TubeTimeUS account makes for an interesting follow, as this person frequently gets into the weeds of hardware diagnostics and debugging.
In the series of posts linked below, @TubeTimeUS investigates a Seagate ST-412 mechanism (same as found in 10MB ProFile drives) and goes through twists and turns to discover that the Track 0 sensor is misaligned and needs shimming. The suspicion expressed is that the plastic just deforms with age. I think there's a similar sensor on the 5 MB ProFile's ST-506.
https://twitter.com/TubeTimeUS/status/1473085565834719233<offtopic>
My own projects have been on a low simmer as I get ready for a house move, but if you'd like to see a non-Lisa related retrocomputing project that I've been busy with, feel free to check out
this github project and
this video 
At some point we may have to worry more about similar issues with Lisa power supplies, although most Lisa ICs are not too hard to replace for now...
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Topic: Track 0 sensor on hard drive mechanisms (Read 18260 times)