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Where to buy Betson-Kortek KT-2914 OSD control board?
lilshawn:
sorry for the lateness of my reply.
i did not know this was a 2 pin variety of switch. typically these boards use a 4 pin variety. but either way....
https://www.mouser.com/ProductDetail/Gravitech/BUTT-2?qs=Vxac6xGyzPn8jCxopasNEg%3D%3D
https://www.amazon.ca/DAOKI-100Pcs-6x6x5mm-Momentary-Tactile/dp/B07X8T9D2Q
https://www.amazon.ca/Momentary-Tactile-Breadboard-Friendly-QTEATAK/dp/B07WF76VHT/ref=pd_lpo_2?pd_rd_i=B07WF76VHT&psc=1
this is a more appropriate part. it is the 2 pin variety. the button portion itself is a standard size, commonly the only differences is the length of the actuator stem. those ones are what i would call a "regular" size and not a "long" one.
if you would like to search for this part on your own local site or shop, this type of switch is most commonly called a "Tactile switch" this one being a "2-pin" opposed to a 4-pin, which I linked before. Sorry, i did not know that particular board was using a 2-pin variety as most of the UI control boards use the 4-pin type.
jimj:
Thanks lilshawn for the additional details, that button looks like a drop in replacement (once I learn how to solder :)). I did notice one more thing about my problem that concerns me. When I press my my "MENU SELECT" button (SW402) it behaves something like this:
10% of the time it does the correct action
60% of the time it does nothing
30% of the time it does the "UP" button (SW403) action
That last "UP" button action has me worried. Any wild guesses how/why that would happen? All of the other buttons (including UP) work correctly 100% of the time. I'm surprised that my MENU SELECT button would frequently send another button's command. Do you still think replacing my MENU SELECT button will fix this? Or I have gone into the weird zone where anything is possible? :)
lilshawn:
the way these work is by having 2 wires going to the computer on the main board. when you press the button on the UI panel, it applies a resistor across the 2 wires. (this is what all the resistors on the ui panel are) all the buttons have a different resistor value. the computer measures the resistance on the line and if it's between such and such a value it's this button that was pressed... but if it's between this and that, its a different button....and so on.
typically when these button fail you get a resistance across them when you press it down (usually corrosion, oxidation, or moisture/dirt infiltration)
this additional resistance throws off the reading the computer gets when you press the button, making it think you pressed a different button. (because the value now falls into one of the other buttons resistor value.
jimj:
--- Quote from: lilshawn on April 11, 2022, 02:47:25 pm ---the way these work...
--- End quote ---
Very interesting, it all makes sense now, thanks for sharing. Sounds like a new button is indeed the cure for this.