Refer to the layout diagram for clarification of parts placement. All references to up, down, left, and right assume that you are looking at the PCB with the silkscreen TAPR logo oriented up on the board. Unless noted otherwise, all components are mounted on the top of the PC board.
The following procedure is used for all sockets to be installed:
1 Sockets normally have pin one identified by a notch in the plastic frame, a ‘1’ stamped on the frame by pin one, an opening in the frame at one end, or a combination of all these. Be sure and identify pin one before proceeding. 2 Likewise, the printed circuit board should have pin one identified with a dot beside it, a notch in the silkscreen pattern, or both. 3 Be certain all pins are straight and none are broken off or folded under. 4 Carefully insert the socket into the holes on the printed circuit board with pin one on the socket oriented to pin one on the board. 5 Holding the socket in place, turn the board over so that the pins are facing up (solder side). The previously installed SMDs and resistors should not interfere with the socket sitting flush to the top of the board. 6 Solder only the two opposite corner pins. 7 Warning! Use something to insulate your fingers in the following procedure as the IC pins will get very hot in the following procedure. Apply gentle pressure to the top of the IC socket while re-heating each of the corner pins. This should cause the socket to seat squarely on the board. Often, you will hear a click as the socket seats after reheating each pin. 8 Visually inspect the socket to be certain that it is squarely seated on the PC board on all sides and that it is correctly oriented. If not repeat the previous step(s) until it is. 9 Once the socket is squarely seated, Solder the remaining socket pins to the board. 10 Go back and re-flow the two corner pins that were initially soldered. Re-flow means to reheat the connection and apply a very small amount of additional solder (the additional solder is only to get flux flowing into the connection again). This is an important step. Failing to do this may result in cold solder joints on these two pins. 11 Using a magnifier, check all pins for solder bridges. The connections should be shiny and bright with no blobs of solder hanging on the pins. It is not necessary to trim the pins.
All sockets are installed using the same procedure as outline above. Install the three IC sockets listed below.
|8-pin DIP socket at U15. Pin one (or the notch) is oriented towards the top edge of the board.|
|14-pin DIP socket at U7. Pin one (or the notch) is oriented towards the top edge of the board.|
|16-pin DIP socket at U10. Pin one (or the notch) is oriented towards the bottom edge of the board, not the top.|