Rosemount 6888Xi, Reference Manual, Page: 98 / 114

90 Maintenance and Service
Section 5: Maintenance and Service Reference Manual
January 2019 00809-0100-4892
8. Disconnect the keypad overlay ribbon cable from the CPU board. Discard the used front
cover with the keypad overlay attached.
9. The keypad window on the new front panel may be supplied with interior and exterior pro-
tective membranes. Remove the protective membranes prior to final assembly and use of
the 6888Xi enclosure.
10. Clean the inside of the keypad overlay window and LCD display window to remove finger-
prints and accumulated dust. Use only a soft cloth; do not use any detergents or chemicals.
11. Connect the keypad overlay ribbon cable on the new front panel assembly to the CPU
board. Use care not to damage the board.
12. Position the CPU board in place in the front panel assembly.
13. Reinstall the bumper and 4 screws to secure the CPU board in place. The two longer screws
are used with the plastic bumper on the top edge of the CPU board.
14. Position the front panel assembly and reinstall the hinge pin. Ensure the hinge pin is fully
seated into the 6888Xi cover.
15. Reconnect the 10-pin ribbon cable from the I/O Board.
16. Reconnect the 14-pin ribbon cable from the Power Supply Board.
17. Swing the 6888Xi cover up in place and tighten the four screws.
18. If necessary, reconfigure the appearance of the main display. Refer to Section 3:
Configuration, Startup and Operation.
5.5.5 DR Board Replacement
Use the procedure that follows to replace the DR board in the 6888Xi that is connected to a
Direct Replacement probe.
1. Loosen the four screws securing the 6888Xi cover. The screws are captive and do not need
to be completely removed.
2. Swing the 6888Xi cover down to expose the inner components.
3. Slide the DR board part way out of the 6888Xi enclosure.
4. Unplug the wiring harness plug from the connector J8 located on the bottom, left-hand side
of the board. Refer to Figure 5-10.
5. Unplug the wiring harness plugs from the connectors J1, J2, and J3 located on the top, right-
hand side of the board. Refer to Figure 6-11.
6. Tag and disconnect the wiring to connector J4.
7. Remove the DR board from the 6888Xi enclosure.
8. Partially slide the new DR board into the mating slots in the 6888Xi Enclosure. Make sure
the board is correctly aligned in the slots.
WARNING
Disconnect and lock out power before working on any electrical components.
NOTE
Prior to assembly, it is recommended that the inside of the keypad overlay window and LCD display window
be gently cleaned to remove fingerprints and accumulated dust.
The calibration parameters are stored in both the I/O Board and Transmitter Board. When the I/O Board is
replaced, the calibration parameters must be either transferred from the Transmitter Board or the entire
instrument must be recalibrated.
NOTE