You can try cleaning the two half circles with very clean pencil eraser (if it 
fits on hole) then with an alcohol soaked qtip. If that does not work it might 
be a break in a PCB trace.

 

Jeff

 

From: M100 <[email protected]> On Behalf Of Thomas Morehouse
Sent: Saturday, July 5, 2025 4:25 PM
To: [email protected]
Subject: Re: [M100] SPAM-LOW: 102 failing keys

 

Jeff - thanks for the suggestions.

 

I popped the plastic key off the numeric 9 key, then removed the rubber cap to 
expose the two metal half-circles.

 

I figure the metal stud in the rubber cap completes the circuit when pressed, 
connecting the two half circles.

 

I then used a steel flat head screwdriver to "complete the circuit".  No dice.  
No change.

 

Can you suggest what my next step would be?  I'm happy to attempt cleaning that 
area of the PCB, but don't know how to proceed.

Thanks.

Tom M.

 

 

On Sat, Jul 5, 2025 at 9:58 AM <[email protected] 
<mailto:[email protected]> > wrote:

Could be the individual keys, could be corrosion on the PCB. Looking at the 
schematic shows none of them have a common row/column in matrix so it is 
probably a problem with individual keys. 

 

Easiest thing to try is pressing easy key firmly about 50 times. If you are 
lucky this will bring it back to life. The T102 keys are harder to pop apart 
and repair than the M100. After 50% of the time it seems like the break (the 
ones with plastic retainer clip are the most likely to break.)

 

Jeff Birt

 

From: M100 <[email protected] 
<mailto:[email protected]> > On Behalf Of Thomas Morehouse
Sent: Saturday, July 5, 2025 7:42 AM
To: [email protected] <mailto:[email protected]> 
Subject: SPAM-LOW: [M100] 102 failing keys

 

My spare M102 works fine - except for three keys not functioning.  Numeric 9, 
alpha O, alpha L.

 

No response on screen whether lower case, shifted upper case, or NUM.

 

The three keys are in a diagonal row.

 

How should I go about tracing the problem, and repairing?

 

Thanks.

Tom M.

Eastford CT

 

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