HP QMS 1660 - Manual (Page 171)

Intellifont
Proms
6-33 Printer Options
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 Access the printer controller board.
Use the instructions in the “Removing Printer and Controller
Board Covers” section of this chapter.
2 Position the controller board so the interface panel is on your
right.
3 Locate the appropriate PROM sockets.
The sockets in which the Intellifont PROMs will be installed are
MR40, MR41, MR42, and MR43.
4 Gently work each PROM into its socket.
Because of the difficulty in removing a PROM once it is installed,
it is important that you read the following information carefully
before you begin inserting the PROMs.
MR43
MR42
MR41
MR40