What happens to my Model M 1391405?

[Delstatenthule]

Hello friends, it turns out that for a while when I press the button "M", automatically and simultaneously, the key "," is pressed, which is next ... is hopeless, I don't know it may be

One day I open the keyboard and I cleaned the inside, but I did not remove the PCB, just wiped the dust that is above the PCB ... and by magic I solved it and until he has done it again a few days ago.

What happens?

[mich]

To me it looks like some mechanical problem in the switches. Remove affected keys and check if there is no junk in the barrels, especially under the hammers.

[Delstatenthule]

To me it looks like some mechanical problem in the switches. Remove affected keys and check if there is no junk in the barrels, especially under the hammers.

How do I remove the PCB to check?

[mich]

You don't need to open the case, let alone touch the PCB. Keycaps are removable from outside, just lever them with a screwdriver.

[rknize]

What happens when you pickup the keyboard and pitch/shake it around?  Do you hear anything clattering around in there?  If you have broken rivets, this could cause weird behavior.  Look down between the rows when you have the keycaps out in the problem area.  See any cracks in the black plastic?