CMU MODULE Replacement
1100.4903.82 3.41 E-4
Replacing the DIGITAL BOARD
(see chapter 5, spare part list, Current No. 570 and explosion drawing 1100.0008.01 D sheet 2)
The DIGITAL BOARD is incorporated in the module support as plug-in module. For replacement
proceed as follows:
Opening the instrument and removing the DIGITAL BOARD
½ Switch off the instrument, pull the mains plug and unscrew the rear-panel feet.
½ Place the instrument onto the front carrying handles, push the tube upwards and take off.
½ After unscrewing the two countersunk screws at the top left instrument frame, slightly lift the cover at
the instrument top, slightly push to the right and lift off.
½ Pull off all the MMCX plug-in cables (using a pull-out tool
∗
) from the top of the DIGITAL BOARD and
pull off the module towards the top using the two levers on the right and left.
Installing the new DIGITAL BOARD and completing the instrument
½ Insert the new DIGITAL BOARD into the instrument in the reverse order and connect all the MMCX
plug-in cables.
½ Complete the instrument without causing damage to the cables.
½ Connect the instrument to the mains and switch on.
Automatic module data adjustment
½ During startup observe the display.
½ When three BEEPs can be heard, press the MENU SELECT key.
The version manager is started (see also chapter 4, Firmware update). The display includes the
menu item FIRMWARE UPDATE AFTER BOARD CHANGE.
½ Press the softkey to the left of the above mentioned menu item.
The automatic module data adjustment is performed under software control, firmware updates for
microprocessors and programmable devices being performed as well. This may take a few minutes.
After the adjustment has been terminated, the operating software starts automatically and the CMU is
ready for use and complies with the specifications, except for the high-precision level accuracy.
In order to achieve the level accuracy as described in the data sheet, a so-called path error data record
is necessary.
To this end, the CMU must be measured using the test system ACS 100 (see chapter 1, Performance
Test).
∗
available in CMU-Service Kit CMU-Z3 (1100.7690.02)