Back in the 90's I worked as a field engineer and had a few of these on contract. They're really nice machines to work on and a common task was replacing these

Back in the 90's I worked as a field engineer and had a few of these on contract. They're really nice machines to work on and a common task was replacing these hard disks when they failed. The IBM field service manuals were pretty good and you could repair/replace pretty much anything on-site. They look like monsters but they're actually really friendly to field service techs.