This is the old keyboard that came with the Mac 128/512/Plus?
Opening it is simple as it is 6 screws I think, and pulls apart with ease. You can wash the plastics while looking at the actual keyboard. They are the same switches used on the IIe and later II+. The IIc uses a smaller version of the same switch.
Check the solder side for broken solder joints. If any are found, desolder, clean the area and solder with fresh solder. Check the solder around the jack and check the traces from switch to switch. that should improve things.
But for bad switches, god... there are a few tricks. Get a lasagna tray and fill it with high proof rubbing alcohol. Dunk the keyboard in it and slosh it about for a while. A long while. It will rinse out the crap inside the switches. Let it dry out and try it out.
If the switches are actually broken, there are replacements. Like I said, IIe and newer II+ keyboards used the same switch. And it is a standard unit. If you can desolder one from the board, the model number is on the bottom of the switch next to the pins. Just need to track it down. Mouser might have it. Newark might have it. JDR(?) Micro Devices might have it.
Opening it is simple as it is 6 screws I think, and pulls apart with ease. You can wash the plastics while looking at the actual keyboard. They are the same switches used on the IIe and later II+. The IIc uses a smaller version of the same switch.
Check the solder side for broken solder joints. If any are found, desolder, clean the area and solder with fresh solder. Check the solder around the jack and check the traces from switch to switch. that should improve things.
But for bad switches, god... there are a few tricks. Get a lasagna tray and fill it with high proof rubbing alcohol. Dunk the keyboard in it and slosh it about for a while. A long while. It will rinse out the crap inside the switches. Let it dry out and try it out.
If the switches are actually broken, there are replacements. Like I said, IIe and newer II+ keyboards used the same switch. And it is a standard unit. If you can desolder one from the board, the model number is on the bottom of the switch next to the pins. Just need to track it down. Mouser might have it. Newark might have it. JDR(?) Micro Devices might have it.