It is quite possible to replace the cherry switches on any PCB, tools you will need and those to open the keyboard obviously, replacement switches of the correct grade, They come in different pressure settings, color coded. A soldering iron, one with a temperature setting facility, these switches will be damaged by temps over 350c so be careful, and a method of removing spent solder from the PCB when you de-solder the switch base, woven copper tape of a solder sucker work fine on these. an of course a rel of silver solder.
Method: first locate the faulty switch, and trace the four contacts beneath it through to the reverse of the board, mark these with a permanent marker dot next to each soldered contact to be worked on,
Run your iron for several minutes to ensure and even heat then gently apply this to the soldered contact on the reverse of the PCB, this should only take a few seconds to melt the solder, remove the heat and quickly apply your sucker or tape to collect the melted solder, it may take a few tries to totally clear the contact area od solder but it must be free of all solder,
Once done move to the other three contacts and repeat the process, Be patient, do not apply too much heat or you risk lifting the PCB tracks, and again BE PATIENT, it is a simple task but if you rush it be warned it will not end well for your board.
Once all the contacts are clean the switch base should simply lift away from the upper face of the PCB, if it will not move don't use force, look again at the contacts as it is probably still solder that is holding it there, You should be able to clearly see the contact wires protruding from the switch base through the board and that they are clear of solder contact.
Having removed the switch base wipe the contact faces of the PCB with a clean lint free cloth, don't use any cleaning spirits as this will damage the coatings on the board, Next offer up the new switch base adjusting the wires as required so they fit cleanly into the four holes into the PCB, once your satisfied it fits neatly into the holes, use your iron and solder to 'tin' the contact wires, apply as little solder as you can here or the wires will not fit into the PCB holes when you offer it up again and again use as little heat as you can, if your iron is set to 350c you should be fine with this process but again be warned to much heat and the switch will be rendered useless.
Once you happy all four have been tinned push the base into the holes in the PCB and then hold the base in place while you turn over the PCB and then neatly bend the protruding wire contacts outwards so the switch base is held tightly into the face of the PCB.,,, The base of the switch must be tight against the face of the PCB, it is going to take a lot of punishment over time, if it is not pressed home that force will be transferred through the board to the solder tracks on the back of the PCB and they will left away and break.
Once you are satisfied it is in place correctly Solder the connections back to the PCB, again use as little heat as you can and as little solder as required, just enough to fill the hole and make contact with the track.
Lastly once completed wipe the solder caps clean, replace the key cap, plug in the board and test your work, The LED should light up and the key work in the true sense, if all is well then assemble the board again and your done.
Most if not all components are easily obtained on the internet.
Facebook
Twitter
Instagram