IBM B50 - Manual (Page 158)

5. Locate and unplug the fan, and disconnect the fansink assembly power cable
from the CPU fansink connector (J26).
Note: There are two possible fansink connections for this system board:
right-angle finger tabs, and wire springs.
Fansink Location
6. To remove a fansink with right angle finger tabs, unclip the heatsink by pushing
down and away on the fingertab. Remove the fansink assembly and discard.
Note: Do not wipe off the remaining thermal grease from the top of the existing
CPU chip on the system board.
7. To remove a fansink with wire springs, push down and away on the wire loop to
disengage the fansink assembly. Gently lift the fansink vertically up and off
without rocking the fansink.
Attention: While removing the closed loop fansink, severe damage may occur
that would require replacing the entire system board assembly. To minimize the
risk for system damage, be sure to perform the above operation no less than 30
seconds after powering off the system, while the heatsink is still hot. Warm
7-14 7046 Model B50 Service Guide