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geekhack Community => Keyboards => Topic started by: jcoffin1981 on Tue, 05 July 2022, 22:39:18

Title: Multiple keys chattering at the same time
Post by: jcoffin1981 on Tue, 05 July 2022, 22:39:18

My work computer is a Leopold FC980M.  And has been operational for about 1.5 years or so.  It contains Cherry Brown switches which have been lubed.  I have noticed in the last month that several, perhaps 8 or so have begun to chatter.  Is this most likely a simple switch issue (seems like a heck of a coincidence) or is there maybe some issue with settings.  I'm not really supposed to install software on these computers, but maybe I can run Switch Hitter from a USB to learn a little more info. Just seems a little odd that so many switches should fail at the same time.  Cherry Brown are supposed to be reliable too.   It would be a PITA to lug it home and swap out the switches.  It's also a PITA to have to delete multipe keystrokes all day.

Title: Re: Multiple keys chattering at the same time
Post by: suicidal_orange on Wed, 06 July 2022, 03:10:11

Are they all the heavily used letters that could be wearing out?  Or maybe it's a whole row or column in the matrix suggesting a dodgy controller pin or damaged trace heading to the controller?  A quick search for a pic of the PCB shows some groups of 4 diodes and some in 2s so at a guess it uses U shaped columns so it would be alternating switches across a row or something like 5TGB6YHN.  This is assuming they haven't changed the PCB as the pic I found is from 2016.

Title: Re: Multiple keys chattering at the same time
Post by: jcoffin1981 on Thu, 07 July 2022, 20:25:24

I've never had a switch wear out.  Well MAYBE one in 10 keyboards.  I'm at home now, but if I recall it is _, a, s, 1, 2, and I know there are a few more, and those may not be entirely accurate.  The only work I've done is lubing the switches about a year and a half ago.  I think I bought them elsewhere.  I'm not really a hard typer, though I am on this board at work.

How do I go about diagnosing this?  Should I just go ahead and replace the switches that are acting up?  Actually, maybe these are Box Browns, IIRC.  Maybe these are not as hardy as genuine Cherry?

Title: Re: Multiple keys chattering at the same time
Post by: suicidal_orange on Fri, 08 July 2022, 03:57:31

Unless you type 12 a lot 12AS looks like a possible column failure, QWZX you don't use often so wouldn't notice?  If this is right I'd reflow the pin that's connecting that column back to the controller chip, just add some flux or fresh solder with flux in to the heated joint.

First thing is working out which keys are broken, then if they are connected to each other or random.

Title: Re: Multiple keys chattering at the same time
Post by: Leslieann on Fri, 08 July 2022, 09:30:56

I could be wrong but,

Seeing as you had to lube then solder, it's likely you over heated and damaged the switches or some lube got in the wrong spot.
In my (limited) experience BOX tend to do it more than Cherry.