MACHINE PIN SOCKET AT U18 (L9) AND U25 (L11-11C)
Use solder wick to remove ALL solder from socket pads on both top and bottom sides. IC should easily pull out of CPU when completely desoldered. Any solder still present can pull up traces and pads.
On stubborn pads- put a little solder back into pad to act as a primer for solder wick.
When all 24 pads are cleaned off, use solder wick to remove any/all tiny pieces of residual solder anywhere in the area. Clean board with rosin remover.
Place socket into board as shown. It should be raised up so that shoulders of pins are slightly above surface of board.
Reverse side pins should look like this.
Finished soldering shows solder filets on all pins.
ADDITIONAL INFO FOR MACHINE SOCKET INSTALLATION
Extra care is needed when working on level 9-11C boards.
Minimum tool recommendation- 30 Watt Pencil and Solder wick (Radio Shack).
If there is a socket in place (U18 in L9 CPU or U25 in L11 thru 11C) and it is clean and tight, plug Simtek adapter (with socket attached) into existing socket. Xtra socket (provided) allows for better clearance of adapter near other components.
http://pin-logic.com/how_to_install_a_machine_pin_soc.htm might be of some help.
Removing battery holder can reveal past corrosion (if any) from years of leaking dry cells.
Note that pins on bottom of adapter and machine pin sockets have high tensile strength but are not malleable.