IC's ,(Intergrated Circuits,those small rectanglar objects on the circuit board with flat wires, or 'leads' extending out from the long sides and bent down 'n thru holes on the circuit board and soldered in place), can have 4-40 leads, the one on the circuit board will have 14 or 16. 7 or 8 to a side when viewed from the top. Looking at the IC from the top, Pin One is at top left and the pins are counted down the left side and then up the right side, so if there are 7 pins on the left side pin number 14 will be directly across from pin 1. To identify pin one, it will either have a 'dot' next to it or the 'top' of the IC will have a half round indententation on the short side of the IC between pin one and pin 14, or 16. Common practice is to mark pin one on the solder side (bottom or reverse of where the components are mounted) with a square pad or soldering point, the other pins will have round or oblong pads. So, to find pin 7, first find pin one and count down the left side and continue, if needed, up the right side of the IC (looking at it from the top!). Use an Exacto knife to cut the copper 'trace' leading to pin seven (Traces may be on either side of the PC board). Note that even though the traces are copper they may have a green 'mask' covering them.

Typical IC pinout samples:
[Link: mameworld.net]

Have Fun

O

This message was edited by ONEAC on 11/30/03 10:36.