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Service
Model 8901B
NOTE
The following operation should be done i n a well ventilated area. If the heat
staking tip
is
too hot, the plastic will vaporize and emit fumes. These fumes,
however, are non-toxic.
HEAT STAKING
BACU SIDE OF
CIRCUIT 8 0 A R D
SOLDER
TIP
MODIFIED AS
SUPPORT
ANVIL
CORRECT
TEMPERATURE
Figure
8C-2.
Typical Assembly
for
Heat Staking Operation
6.
To assure proper switch assembly, verify that the switch
is pushed firmly against the circuit board
and, with the hot
(44OOC
or 825°F) staking tip, push down on each of
the
posts (2) of the switch.
Each post should take about one second to stake. With the proper cycle, the post should turn a
darker color and, in about ten seconds, return to its original bright red color. The correctly staked
post should have a smooth round "rivet" like top.
Do not disturb the assembly for at least
10 seconds after heat staking.
If not enough heat is applied, the plastic will tend to stick to the tip of the
iron.
I f too much heat
is
applied, the plastic will fume profuse13 the "rivet" will
be irregularly shaped, and the plastic will be permanently discolored.
If the staking tool is worn or Baked,
it will cause a misshaped rivet andlor
a contamination deposit o n the surface.
8C-4
Disassembly Procedures
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