SmartSeis
TM
Maintenance Manual
10
The system can be powered-up and operated outside the plastic case. In general, we suggest
that you turn the unit on and confirm that the seismograph functions properly after a repair and
before reinstalling the seismograph in its case.
2.2 Replacing an acquisition board
The SmartSeis
TM
acquisition boards are located beneath the OMNI board (Figure 3), numbered
in order, from 1 to N, starting with the lowest number. The channels that correspond to each
board increase in sets of 12. For example, the board in the top-most slot will be board number
1 and contain channels 1 through 12. For a 24-channel seismograph, the board in the next slot
will be board 2 and contain channels 13 through 24. If a board is missing or has failed in a way
that it is invisible to the software, it will not be numbered.
To remove an acquisition board:
1. Confirm that the power is off and the power cable disconnected from the seismograph.
2. Remove the four Philips screws and the retaining bracket holding the acquisition board in
place.
3. Disconnect the power distribution cable from connector J2, the 10-pin ribbon cable
located on the left and topsides of the board (Figure 2).
4. Disconnect the geophone ribbon cable, the 26-pin ribbon cable located on the left side
of the board (Figure 1). Spread the connector locking levers open to facilitate sliding the
connector past the chassis.
5. Carefully and gently ease the board loose from its backplane slot, slide it out of the
slotted card guide that is integrated into the right-hand-side of the chassis (Figure 1) with
even pressure on both sides; continue to remove the board.
A board installation is the reverse of a removal. Before installing a new board, you must check
that the jumpers are properly set (see
Section 2.2.1, Acquisition board jumper settings
).
When reconnecting the ribbon cables, be very careful so that you do not bend the connector
pins or nearby capacitors. Also, each replaced board needs to be fully seated into its
backplane slot, reslotted into the card guide, and squarely aligned with the chassis and the other
boards.
As mentioned above, we suggest that you turn the seismograph on and confirm that it is
functioning properly after the repair and before reinstalling the seismograph in its case. If the
board is receiving power, the LEDs will be lit.
