HP QMS 1660E - Manual (Page 174)

Optional
Interfaces
QMS 1660E Print System Reference 6-40
▲ Caution: It's very important to protect the printer controller board from
electrostatic damage while performing this task.
If an anti-static wrist strap is provided in your printer option kit,
attach one end of it to your wrist and the other end to any convenient
electrical ground (for example, the bare metal chassis of equipment,
as on the back of a computer, that is plugged in but turned off).
Never attach the wrist strap to any piece of equipment with an
electrical current present. Turn off all power switches first. Plastic,
rubber, wood, painted metal surfaces, and telephones are not
acceptable grounding points. The printer isn't an acceptable
grounding point either because it must be unplugged before you
perform this task.
If you don't have an anti-static wrist strap, discharge your body's
static electric charge by touching a grounded surface before you
handle any printer boards or components and before removing the
controller board cover. Redischarge your body’s static electric charge
each time after walking around and before touching the printer
controller board again.
1 Turn off the printer, and then disconnect the power cord and
all interface cables (parallel, serial, and Ethernet) from the
printer.
2 Access the printer controller board.
Use the instructions in the “Removing the Printer and Controller
Board Covers” section of this chapter.