It actually looks like the spring on the "wedge" shaped / crashed head has been bent, which would be a problem...
--tom On 12/22/19 9:48 AM, Chris Zach via cctalk wrote: > So after looking at the mess the mice had made of my third RL02 drive I > decided it would probably > be better to pull the heads and put them in my second drive (the one with the > bad top head and > plugged filter). > > Getting heads out was simple, and I decided to put them side to side with the > heads in drive 2. > The following images show some interesting details. > > https://i.imgur.com/tcmkUmO.jpg > > Note that O is original (the heads from drive 2) and the top heads are from > drive 3. > > First, the heads on the third drive were in pretty good shape and looked > clean. Under the loupe > though I could see some fragments of gunk that needed to be removed. More > importantly I did a side > view comparison between the bad top head in #2 and the top head in #3: > > https://i.imgur.com/D6HOxND.jpg > > This was a really tough picture to take, and you have to zoom in on the heads > in the upper right. > But what you can clearly see here is that the better head from #3 (left one) > is pretty much > rectangle shaped while the crashing head from #2 (right one) is shaped like a > wedge, with the top > part being narrower than the bottom. > > https://i.imgur.com/fEGuOFE.jpg > > And of course the filter removed from #2. Note the silicon sludge, I think > this is 100% blocked > (and was why the drive made a lot of air/wind noises when spun up, the fan > was cavitating) > > This sums it up: I think what happened is the unit was run in a very dirty > environment, the > absolute air filter plugged up, and the heads don't fly as well without that > blast of clean air > coming in. So they dragged on the disk, and the ceramic rubbed off (and onto > the packs) which led > to the eventual disk damage. > > Moral: Change filters. I cleaned up the #3 heads, put the heads from #3 into > unit #2, put the air > filter from #3 into #2, and fired it up with the test pack. Goes to ready no > problem, will do a > full dir/bad with RT11 later this afternoon to see if I still have two errors > on the pack. > > It is interesting to note that the bottom head from drive 2 didn't look too > bad, and did not pick > up any dirt/oxide from the disk after I replaced the filter. It was probably > flying very close to > the platter but had just enough airflow to make it fly. Still, I'll put it in > the spares pile and > think about it for awhile... > > Otherwise, back in business. I'll be checking the filter on #1 just to be on > the safe side. It was > my RL02 drive from 30 years ago and was not one of the Solarex ones. Then > I'll put fixing this > third RL02 on the calendar (will need new wiring, long ribbon cable, filter, > heads, and a massive > clean-up inside), and start working on restoring my darn RSX11M 4.2 disk > packs... >
