Tektronix 491 Maintenance Manual page 2

is used in the operation of this equipment.
may result if personnel fail to observe safety precautions.
Learn the areas containing high voltage
Be careful not to contact high-voltage or 115-volt ac input connections
when installing or operating this equipment.
Before working inside the equipment, turn power off and ground points of
high potential before touching them.
WARNING
HIGH VOLTAGE
DEATH ON CONTACT
in each piece of equipment.