On 05/30/2019 02:20 PM, shadoooo via cctalk wrote:
I'm in the process of cleaning and hopefully restore to operation of a DEC
The unit has some minor sign of corrosion, however it's VERY dirty, even
inside the hood.
The filters are obviously to be removed and replaced, as they are
Also foam parts between the boards must be replaced.
Aside from obvious parts, there's something that should be replaced /
cleaned inside the HDA (foams, filters or rubbers), which could damage the
disk permanently in case it's turned on after decades if not "cured"
Anybody has some good pictures of the HDA inside, after cover removal?
I don't think this is a field procedure. Definitely, way
back around 1980 or so, they had some bum adhesive that held
the internal filter in the RA80 and RA82 HDAs, as I recall,
and they had to replace all HDAs in the field, over time.
They had some scheme where the oldest HDAs were replaced
first, as the adhesive degraded over time, so they knew they
had a couple years since new before the problem would
occur. It was a BIG expense for DEC.
Presumably, all of these HDAs (that were under maintenance
contract) that had the bad adhesive in them were replaced
years ago. As far as I remember, there IS no removable
cover on those HDAs, they were hermetically sealed except
for a tiny, filtered, pressure relief vent.
I think the procedure to update those HDAs was a pretty