Rockwell Automation 8520 9/Series CNC Integration Maintenance Manual Documentation Set - Manual (Page 791)

Section 15B
Replacement Procedures
15B-35
7. Remove the 9 mounting screws along the top and bottom edges of the
MTB interface board.
+12V DC
GND
OP11
(out)
OP12
(in)
JPR1
JPR2
CN51
CN52
MTB Interface Board
TB1
TB20
8. Remove the interface board to reveal the MTB board that contains the
push-buttons.
MTB Board
9. Use a flat head screwdriver to twist the bulb and its socket out of the panel.
10. Place the replacement bulb into the hole and gently twist the socket
into place.
Important: Do not over-tighten the light bulbs.
11. Remount the MTB interface board and reconnect the cables and
wiring you disconnected in steps 3. through 6.