User manual

LPC4357 Developer’s Kit - User’s Guide

Page 54

5.5 Handling SO-DIMM Boards

See picture below for instructions about how to mount/remove the LPC4357 OEM Board.

To install the OEM Board, align it to the socket (1). Push the board gently, and with even force

between the board edges, fully into the socket (2). Then push the board down in a rotating move (3)

until it snaps into place (4). The OEM Board shall lie flat and parallel to the base board.

To remove the OEM Board, spread the two arms of the SO-DIMM socket apart slightly. The board will

pop up (5). Gently rise the board in a rotating move (6) and then extract the board from the socket (7).

Apply even force between board edges when removing so that the board is removed parallel to the

locking arms.

Figure 33 – Instructions how to Mount/Remove the LPC4357 OEM Board

Do not forget to follow standard ESD precaution routines when mounting/removing the OEM Board.

Most signals exposed on the 200 edge contact fingers on the SO-DIMM board are unprotected.

Maintain the same electrical potential of the OEM Board (to be mounted) and the base board. Do not

touch the OEM Board edge connectors. Handle the OEM Board only by the three other edges. Also,

do not touch the components on the board.

5.6 Things to Note

This section lists things to note when using the LPC4357 OEM Board and the OEM Base Board.

5.6.1 Humming in Speaker

In some situations there can be a humming sound from the on-board speaker. This is because of high-

frequency noise on signal GPIO40_AOUT. The layout in the base board has not been design for

lowest possible noise. If the sound is disturbing, just remove both jumpers in JP29 (see section 4.25

for locating the jumpers). Alternatively, add a 100nF ceramic capacitor in parallel to R239. See Figure

34 below where to locate R239. The capacitor will create a low-pass filter removing the noise in the

audible region.