41cx on button - Printable Version +- HP Forums (https://archived.hpcalc.org/museumforum) +-- Forum: HP Museum Forums (https://archived.hpcalc.org/museumforum/forum-1.html) +--- Forum: Old HP Forum Archives (https://archived.hpcalc.org/museumforum/forum-2.html) +--- Thread: 41cx on button (/thread-81945.html) |
41cx on button - hal - 11-12-2005 Hi folks, Re: 41cx on button - Diego Diaz - 11-12-2005 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.
Re: 41cx on button - hal - 11-12-2005 Thanks Diego for your response. Re: 41cx on button - Diego Diaz - 11-13-2005 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.
Re: 41cx on button - Dave Bernazzani - 11-15-2005 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.
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