Bio-Rad CHEF Mapper® XA System - Manual (Page 6)

Unplug these two connectors from the board. The lower (blue) one has two clips on the top
and the bottom. The picture above shows the clip on the bottom in the open position. Open
the clip on the top as well, and unplug that plug. The plug on the top is unplugged by pulling
it gently from the connector on the board.
7. Identify the ROM chip U12 behind the two tallest integrated circuits (U13,U14) at the
bottom half of the Processor I/O Board (near the edge of the card, closest to the back of
the Mapper).
Caution: Memory chips are easily damaged by static discharges. Observe procedures
for handling static sensitive components to keep from damaging the memory chips. Be
sure to ground yourself to metal before touching the components on the board.
8. Using the enclosed IC chip puller, grasp the edges of the chip, carefully removing U12
(label can be seen on the board). Alternatively, a small screwdriver can be used as a pry
to lift the chip carefully out of the socket.
9. Carefully place the new U12 chip in the U12 socket. Make sure that the dot stripe or
notch near the top of the chip matches with the notch on the board. Also, make sure that
the pins of the chip are straight before insertion into the socket. Place the far row of pins
into the socket first, and then the other pins. Then press down on the chip firmly to seat
it into place as shown.
4
U12