How do I fix membrane keys?

[Thorogrimm]

I've recently received an Olivetti ANK27-102 from Ebay and the space bar along with the B and N keys have stopped working after some use. It was working briefly a couple of times but then suddenly decides not to. I've checked the ribbon connector inside and noticed scratches on the contacts, so I snipped the worn parts off for fresh ones to be used. Still no improvement. The PCB is sandwiched together with the membrane and the capacitive sheet so I can't clean the actual contacts themselves if that's what the issue is. Does anyone have any ideas on how to fix this? I still have yet to give into the idea that the keyboard is simply near the end of its lifespan because the switches feel so good on it and every other key works fine.

I've thought about dousing it with isoproyl alcohol but I want some more professional advice on how to potentially fix this issue.
Thanks in advance!

[ddrfraser1]

I've recently received an Olivetti ANK27-102 from Ebay and the space bar along with the B and N keys have stopped working after some use. It was working briefly a couple of times but then suddenly decides not to. I've checked the ribbon connector inside and noticed scratches on the contacts, so I snipped the worn parts off for fresh ones to be used. Still no improvement. The PCB is sandwiched together with the membrane and the capacitive sheet so I can't clean the actual contacts themselves if that's what the issue is. Does anyone have any ideas on how to fix this? I still have yet to give into the idea that the keyboard is simply near the end of its lifespan because the switches feel so good on it and every other key works fine.

I've thought about dousing it with isoproyl alcohol but I want some more professional advice on how to potentially fix this issue.
Thanks in advance!

Any time I've had an issue with a capacitive PBC it's been dust/dirt. After disassembly and a clean with either PCB cleaner in a spray can or isopropyl alcohol, it works just fine. The other thing I would try, since it's all in the same area, is check to see that the PCB and membrane are tight against the plate and caps. It may just be too loose to actuate kind of like a model M in need of a bolt mod. Not sure if that's relevant to this type of board or not. Good luck!

[Thorogrimm]

I've recently received an Olivetti ANK27-102 from Ebay and the space bar along with the B and N keys have stopped working after some use. It was working briefly a couple of times but then suddenly decides not to. I've checked the ribbon connector inside and noticed scratches on the contacts, so I snipped the worn parts off for fresh ones to be used. Still no improvement. The PCB is sandwiched together with the membrane and the capacitive sheet so I can't clean the actual contacts themselves if that's what the issue is. Does anyone have any ideas on how to fix this? I still have yet to give into the idea that the keyboard is simply near the end of its lifespan because the switches feel so good on it and every other key works fine.

I've thought about dousing it with isoproyl alcohol but I want some more professional advice on how to potentially fix this issue.
Thanks in advance!

Any time I've had an issue with a capacitive PBC it's been dust/dirt. After disassembly and a clean with either PCB cleaner in a spray can or isopropyl alcohol, it works just fine. The other thing I would try, since it's all in the same area, is check to see that the PCB and membrane are tight against the plate and caps. It may just be too loose to actuate kind of like a model M in need of a bolt mod. Not sure if that's relevant to this type of board or not. Good luck!

Thanks for the advice. The nature of how the keyboard was made made it extremely difficult to clean the capacitive sheet without breaking off the rivets from the switch housings which held them onto the backplate. Kind of a bolted together sandwich of capacitive sheets using the switch housings. A nightmare. In the end I managed to detach everything, clean it and put it back together in a ghetto fashion using super glue to stick the stems of the switch housings to the back plate, seeing as I'd broken off the rivets. It works alright now, with exception for some of the movement keys sticking and repeating an input in FPS games. If I really wanted to do it properly, I could have screwed through the mounts for the switch housing rivets and screwed them in with fine screws, but... eh.