41cx on button

[hal]

Hi folks,

Does a 41cx On button actuate a discrete micro switch, or is it just part of the keyboard contact matrix.

Thanks, Hal

[Diego Diaz]

Hi Hal,

The CX (all 41 series for that matter) does not have microswiches.

Every key (including [ON]) is handled by the Nut processor keyboard matrix.

Hope this helps.

Diego.

[hal]

Thanks Diego for your response.

I was afraid that would be the case with the on switch. My cx requires a bit of excessive pressure on the switch to turn it on or off. Is there a remedy for that?

Hal

[Diego Diaz]

It's a somewhat common problem on used machines.

Mostly due to some dirtiness between the steel key-dome and the KB PCB.

Light cleaning involves taking your 41 apart, turn the upper half (keyboard) upside down, place one drop (means *just* one) of iso-propyl-alcohol thru the small PCB hole under the afected key(s) while repeatedly pressing such key.

This will fix mostly any not-so-bad key contact. For the severe cases (of dirtiness) you should get a very thin and soft paintbrush. Thin enough to pass thru said small hole, and soft enough to bend its whiskers inside the key dome. DO NOT PUSH, just rotate CW-CCW gently after placing one IPA drop and pay attention not to leave any loose whisker around.

Keyboards with physical damage (not just dirtiness), may require complete disassembling of the KB PCB, which is by no means advisable unless you are a very skilled technician...

Hope this helps.

Diego.

[Dave Bernazzani]

One more thing to add about cleaning with Isopropyl alcohol: make sure you use the 91% Isopropyl alcohol found in most drug stores or larger shopping centers. The 70% (usually sold right next to it) is a few pennies cheaper but contains mineral oils. This will still clean effectively but will leave the surface coated with mineral oils which will attract dirt and other foreign particles rather quickly. The 91% solution contains 9% inert materials (mostly water). If you don't want such as strong solvent, you might want to dilute this further 50/50 with water (distilled water is best... but not necessary). In any event, stay clear of the 70% "rubbing" alcohol.