Keyboard key failure

Recently my MNT Reform2’s keyboard has had a strange problem. The “N” key was producing duplicate key presses. Every time I hit the ‘N’ Key it would produce “nn” :frowning: I pulled the key cap and cleaned out underneath.

While I was dis-assembling the laptop, I figured I’d update the keyboard and LPCP firmware (according to https://community.mnt.re/t/mnt-reform-recommended-lpc-and-keyboard-firmware-update-to-fix-battery-drain-in-off-state/559.)

At some point my ‘n’ key started producing “~7uhn~7uhn”, and capital “N” started producing “;2~&UHN;2~&UHN”.

Not sure if that helps?

I had the same problem!
I’n my case there was that an internal USB cable smushed between the heatsink and bottom cover. This pushed the motherboard closer to the keyboard… and pressing keys pushed the keyboard bottom onto the motherboard, leading to short circuits.
At least this is what I think was happening. The problem went away once I moved the internal cable out of the way.

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Yes, it sounds like a conductor/metal part is touching key pins from the bottom. Check for that and employ tape in strategic locations.

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Pulled everything out and taped off the n key. So the original problem is back. whenn i press the n key, it doubles. Seems like if i press the key downn annd hold it, the second nn comes up onn the key release… typos left for emphesis…

You only taped the n key? It could be the bottom of another key, or some other metal part causing the trouble…

literally pulled the keyboard out of the laptop annd placed the acrylic bottom unnderneath it. I donnt think the problem could be what you are suggestinng…

Bad solder joints on that key or its diode perhaps? That could cause excess bounce on the key signal. Do you have flux and a soldering iron and could touch these up?

I have an iron and flux, but m not especially skilled in the use…

SW47 is the misbehaving key.

So, how does one “touch things up?”

Put some flux on SW47 pins and D47 pads. Set your iron to ~380 degrees celsius. Clean the tip of the iron. Put a tiny bit of solder on the tip of the iron. Heat the SW47 pins and D47 pads so that the solder on them melts, then remove iron (one by one).

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