IBM 6643 - Manual (Page 87)

≥ 32 kg (70.5 lbs) ≥ 55 kg (121.2 lbs)
CAUTION:
Use safe lifting practices when lifting your machine.
CAUTION:
Electrical current from power, telephone, and communication cables can be
hazardous. To avoid personal injury or equipment damage, disconnect the attached
power cords, telecommunications systems, networks, and modems before you open
the server covers, unless instructed otherwise in the installation and configuration
procedures.
Chapter 8. Related service information 79