Fitting SMD Sockets
SMD Sockets
The surface mount PLCC socket (SMD) needs to have the centre backing piece removed. This is necessary so as to be able to solder the pins in place on the board.
The contact points need to be fluxed. It must then be positioned so as all the legs fall over the pads where the Flash BIOS chip was originally fitted, with the 45 degree corner in the right place.
Once you are happy with the alignment, solder two or three pins on the most accessible side with a clean iron. Keep the iron clean and do not linger on the terminals any longer than necessary. A quick dab with an iron is all that is usually needed. Check alignment and if you are happy then proceed to solder two pins on the opposite side of the socket.
The socket should be held firmly in place by now, and you can now proceed to solder all the pins one side at a time By quickly dabbing them with a soldering iron. When you are happy that you have soldered all 32 pins, grab a fine tipped pick or needle file.
Check each pin in turn by gently prodding them with the pick. A magnifying glass is handy for this as you will see them move as you prod them if they are not soldered correctly. No additional solder should be needed there should be enough left on the pads to do the job.
Care needs to be taken whilst checking the soldered Joints, do not apply to much force as you my damage the tracks.
Re solder any Loose connections and recheck them all. Now all that needs to be done is clean the socket interior taking special care to remove any tiny bits of loose solder.
Visually check for shorts. Finally fit a new programmed chip and power on the board and all should be well.
If you replace the chip and you still have a no boot situation then I suggest you carefully check all the soldered connections in the socket. Use a magnifying glass and recheck them carefully prodding each in turn to check if the are firm.
Special care should be taken not to overheat the tracks, and the soldering iron used must be kept clean, and be cleaned numerous times throughout the operation.
Use of excess solder will probably result in solder flowing between the connections of the socket so this should be avoided.
Flux
The flux used for any electrical soldering must be non acidic and designed for use with electronics. Do not use an acidic flux or you will have problems.