The servicing of these boards requires special precautions. It is strongly
recommended to use Lead Free Solder material in order to guarantee optimal
quality of new solder joints.
7
1-7. Lead Free Information
The circuit boards used in these models have been processed using Lead
Free Solder. The boards are identified by the LF logo located close to the
board designation.
Figure 4: LF Logo
Figure 5: LF logo on circuit board
1-6. How to Find a Good Earth Ground
1) A cold-water pipe is a guaranteed earth ground; the cover-plate retaining
screw on most AC outlet boxes is also at earth ground.
2) If the retaining screw is to be used as your earth ground, verify that it is at
ground by measuring the resistance between it and a cold-water pipe with an
ohmmeter. The reading should be zero ohms.
3) If a cold-water pipe is not accessible, connect a 60- to 100-watt trouble-
light (not a neon lamp) between the hot side of the receptacle and the
retaining screw. Try both slots, if necessary, to locate the hot side on the line;
the lamp should light at normal brilliance if the screw is at ground potential
(see Figure 3).
Figure 3. Checking for earth
ground.
To Next Page
Loading...
