Appendix 8 Detecting the Location of a Short on a Printed Circuit Board
A21
Appendix
Comparing the resistance values at multiple locations provides a useful way to infer the
location of a short on an unpopulated printed circuit board. Short patterns X and Y as
described below:
Example
(1) 20 m
(2) 11 m
(3) 10 m
(4) 10 m
Based on the above measured values, the short can be inferred to be near (3).
Appendix 8 Detecting the Location of a
Short on a Printed Circuit Board
1 Connect SOURCE A and SOURCE B to their respective patterns.
2 Connect SENSE A to a point near SOURCE A, and SENSE B to location (1).
3 Observe the measured values as you move SENSE B from (1) to (2), (3), and (4).
Higher resistance values indicate greater distance from the short location. Nar-
row down the short location by moving the SOURCE B and SENSE B terminals.
SENSE B
(1) SENSE B
(2)
(3) (4)
SOURCE B
SOURCE A
SENSE A
i
Pattern X
Short
Pattern Y