Modar Posted August 27, 2016 Share Posted August 27, 2016 Hello there. So I've got a Casio CTK-5000 Portable Keyboard, and I noticed that when the Eb key on the 4th octave is pressed down, D; C; C#; B; Bb; A; Ab (on the 4th octave also) always play at the highest velocity (= 127) no matter how soft I press them, Even though I can't reach that velocity when pressing any key alone even if I wanted to (Max. = 100). What's wrong with that Eb Key? How do I prevent the mentioned keys from sounding really loud when the Eb Key is pressed down? Quote Link to comment Share on other sites More sharing options...
- T - Posted August 29, 2016 Share Posted August 29, 2016 This is indicative of debris (cookie crumbs, cracker crumbs, toast crumbs, pizza crust, dead bug, hairpins, straight pins, needles, etc, etc, etc) under the keys - between the keys and the rubber contact strip under the keys, but that normally affects only a single key or maybe two keys right next to each other. For one key to affect the velocity level of several other keys sounds more like a contact strip or circuit problem, but before getting into that, get a can of compressed air and try blasting it generously under the keys to see if that clears the problem. If it does, then one of the items I mentioned at the start was probably the cause. If it doesn't, then you may be looking at a trip to the service center. The keyboard resets itself each time it is powered on. The is no separate factory reset or initialize function. Quote Link to comment Share on other sites More sharing options...
Modar Posted August 29, 2016 Author Share Posted August 29, 2016 49 minutes ago, tnicoson said: This is indicative of debris (cookie crumbs, cracker crumbs, toast crumbs, pizza crust, dead bug, hairpins, straight pins, needles, etc, etc, etc) under the keys - between the keys and the rubber contact strip under the keys, but that normally affects only a single key or maybe two keys right next to each other. For one key to affect the velocity level of several other keys sounds more like a contact strip or circuit problem, but before getting into that, get a can of compressed air and try blasting it generously under the keys to see if that clears the problem. If it does, then one of the items I mentioned at the start was probably the cause. If it doesn't, then you may be looking at a trip to the service center. The keyboard resets itself each time it is powered on. The is no separate factory reset or initialize function. A guy on Reddit suggested that the problem is caused by a faulty diode, this seems to be true since the total number of keys affected is 1 + 7 = 8 (a matrix). Any idea what type of diodes is used in these keyboards? Quote Link to comment Share on other sites More sharing options...
- T - Posted August 29, 2016 Share Posted August 29, 2016 You would need a service manual to determine that. I am sure the CTK-5000 circuit boards use several different types of diodes, depending upon their particular function and current/voltage requirements in the circuit, So the question is not only what type of diode, but which particular diode. I recommend doing a Google search on "CTK-5000 Service Manual" to see if a downloadable version is available. Quote Link to comment Share on other sites More sharing options...
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