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#1
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hp elite kbd, keys not working
I bought an HP elite v2 kbd because it has such great action, it's the
fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike |
#2
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hp elite kbd, keys not working
Mike S wrote:
I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike Keyboard that use rubber-like membranes with carbon patterns to short across PCB contact points always wear out. The rubber-like compound dries out and becomes more stiff. The "action" is the difference in thickness around the protruding stub that suddenly collapses when flexed beyond a certain point. Because of the physical wear of pressing the carbonized membrane against metal contacts, the membrane's contacts wear out (less carbon, less reliable contact). The more you type, the sooner the membrane fails. You would have to look inside the keyboard to see what technology was used for the "switches". Some keyboards really do still use switches which is why they are pricey. For a $30 wifi thin profile keyboard (https://www.amazon.com/HP-Wireless-E...dp/B005HNHRA6), that one is not using switches. It's a cheap wifi keyboard. Get another one. If that's what you like, buy 2 so you have a spare on hand when the first one breaks or goes flaky (again). A mechanical switched keyboard will run about 5 times, or more, the cost of the one that you bought (and most of the mechanicals are wired, not wifi like you got). I also buy cheap[er] keyboard; i.e., no mechanical switches, just membrane "switches". I buy 2 because the membrane keyboards do not last. I figure that I'm lucky if the keyboard remains reliable (like new) for 2 years, especially since I'm prone to pound on them occasionally (if I got rid of my video games, I'd pound on the keyboards much less often). I have a spare waiting in a drawer because I know that membrane keyboards do not last. They are not built to be repairable. With a mechanical switch keyboard, you can buy a new switch and solder in a replacement key. They aren't built to last. Look at the warranty. Be glad if the product survives beyond then. They know the failure rate of their devices at at which point in the curve to establish a warranty threshold or how much to invest in hardware quality to get minimally beyond the warranty threshold. When was the last time you turned your keyboard upside down, held it with one hand on one side, and banged it against your other hand and then reversed the procedure to know out any crumbs, hair, or other crud that got inside? What you have is not a waterproof keyboard. Crud will get inside. If it manages to get under the membrane (between it and the PCB contacts) then you aren't going to shake it out hence why most warranties won't cover liquid damage. After banging out any crud that got inside, blow it out using a duster can. Often hair and lint won't shake out but you can it blown out. You'll have to blow from several angles as the hair and lint may wrap around the stem of the key or cram into places that require blowing from several directions. |
#3
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hp elite kbd, keys not working
Mike S wrote:
I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike Keyboards use a scanning matrix. For example, a chip could have a 7x17 matrix, using 24 pins. One set of pins are sources, the others detect key closures. When a "set" of keys die, they're probably sharing one of those wires. Only if the contacts under a single key fail, would you lose just one key. When you lose a set of keys, that's a problem with a scanning wire or scanning wire input. Keyboards can be N-key rollover, or 2-key lockout. The N-key rollover, uses a diode per crosspoint in the scanning matrix. It helps isolate one switch closure from another, and prevents things such as "ghosting" if three keys are pressed. Not many keyboards spend an extra five bucks to do that. (I built my own keyboard, and included those diodes on each switch position.) As for the wiring pattern of the "matrix", the letter assignments don't have to make a lot of sense. I needed a fair number of feedthru wires on my PCB layout, to allow wiring connections around one another. My home-made PCB didn't have plated vias, so when a signal went from one layer to another, a wire was soldered through a hole, to join the connections together. The scanning matrix is generally high impedance. Some of the scanning wires might have been up around 100K ohms or so. This means, it might not take a lot of dirt or debris to upset it. Maybe this was an attempt to reduce emissions from the keyboard or something. In addition, the scanning process uses "debounce". When the key closes a scanning matrix location, the conductor does not immediately sit flat on the connection point. There tend to be springs in keyboards, flexible materials, and they cause contact bounce. The keyboard only declares "closure", after three keyboard matrix scans in a row, show the same closure pattern. Then the keyboard knows "it's a sure thing", once it has eliminated the possibility of bounce. The bounce interval selected, should exceed any possible spring time constants. The closest thing to a "bounceless" contact, might be keys with Hall probes and hysteresis. And that would be an expensive keyboard. The keys in that case, use magnetism to indicate their presence. The Hall probe sense a magnet is pressed against it, or not. No contacts to wear out, but the keys themselves can eventually mechanically fail. You can still get 10 million cycles from a membrane keyboard. That's what some of the manufacturers will claim, and there are machines you can use to verify lifetime. We used to have two big machines at work, which used to bash on keyboard-type devices as part of reliability testing. I only got to see those on a walking tour, so never got to ask any questions about why the machines were so big. Paul |
#4
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hp elite kbd, keys not working
On 2/12/2017 6:23 PM, VanguardLH wrote:
Mike S wrote: I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike Keyboard that use rubber-like membranes with carbon patterns to short across PCB contact points always wear out. The rubber-like compound dries out and becomes more stiff. The "action" is the difference in thickness around the protruding stub that suddenly collapses when flexed beyond a certain point. Because of the physical wear of pressing the carbonized membrane against metal contacts, the membrane's contacts wear out (less carbon, less reliable contact). The more you type, the sooner the membrane fails. You would have to look inside the keyboard to see what technology was used for the "switches". Some keyboards really do still use switches which is why they are pricey. For a $30 wifi thin profile keyboard (https://www.amazon.com/HP-Wireless-E...dp/B005HNHRA6), that one is not using switches. It's a cheap wifi keyboard. Get another one. If that's what you like, buy 2 so you have a spare on hand when the first one breaks or goes flaky (again). A mechanical switched keyboard will run about 5 times, or more, the cost of the one that you bought (and most of the mechanicals are wired, not wifi like you got). I also buy cheap[er] keyboard; i.e., no mechanical switches, just membrane "switches". I buy 2 because the membrane keyboards do not last. I figure that I'm lucky if the keyboard remains reliable (like new) for 2 years, especially since I'm prone to pound on them occasionally (if I got rid of my video games, I'd pound on the keyboards much less often). I have a spare waiting in a drawer because I know that membrane keyboards do not last. They are not built to be repairable. With a mechanical switch keyboard, you can buy a new switch and solder in a replacement key. They aren't built to last. Look at the warranty. Be glad if the product survives beyond then. They know the failure rate of their devices at at which point in the curve to establish a warranty threshold or how much to invest in hardware quality to get minimally beyond the warranty threshold. When was the last time you turned your keyboard upside down, held it with one hand on one side, and banged it against your other hand and then reversed the procedure to know out any crumbs, hair, or other crud that got inside? What you have is not a waterproof keyboard. Crud will get inside. If it manages to get under the membrane (between it and the PCB contacts) then you aren't going to shake it out hence why most warranties won't cover liquid damage. After banging out any crud that got inside, blow it out using a duster can. Often hair and lint won't shake out but you can it blown out. You'll have to blow from several angles as the hair and lint may wrap around the stem of the key or cram into places that require blowing from several directions. thanks for the detailed post! I tried turning it upside down, blowing it off, knocking it around a bit, none of that worked. I just took it apart and flooded the kbd with soapy water, sloshed it around, rinsed it, repeat 3x, then flush w/clear water 3x, it's sitting upside down in a warm spot for a few days now to dry out. But as you say it's probably just worn out. Now that I think about it, it is closer to 2 yrs old than I remembered, so if it continues to malfunction I'll just keep it for parts and buy another. Thanks again. Mike |
#5
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hp elite kbd, keys not working
On 2/12/2017 6:46 PM, Paul wrote:
Mike S wrote: I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike Keyboards use a scanning matrix. For example, a chip could have a 7x17 matrix, using 24 pins. One set of pins are sources, the others detect key closures. When a "set" of keys die, they're probably sharing one of those wires. Only if the contacts under a single key fail, would you lose just one key. When you lose a set of keys, that's a problem with a scanning wire or scanning wire input. Keyboards can be N-key rollover, or 2-key lockout. The N-key rollover, uses a diode per crosspoint in the scanning matrix. It helps isolate one switch closure from another, and prevents things such as "ghosting" if three keys are pressed. Not many keyboards spend an extra five bucks to do that. (I built my own keyboard, and included those diodes on each switch position.) As for the wiring pattern of the "matrix", the letter assignments don't have to make a lot of sense. I needed a fair number of feedthru wires on my PCB layout, to allow wiring connections around one another. My home-made PCB didn't have plated vias, so when a signal went from one layer to another, a wire was soldered through a hole, to join the connections together. The scanning matrix is generally high impedance. Some of the scanning wires might have been up around 100K ohms or so. This means, it might not take a lot of dirt or debris to upset it. Maybe this was an attempt to reduce emissions from the keyboard or something. In addition, the scanning process uses "debounce". When the key closes a scanning matrix location, the conductor does not immediately sit flat on the connection point. There tend to be springs in keyboards, flexible materials, and they cause contact bounce. The keyboard only declares "closure", after three keyboard matrix scans in a row, show the same closure pattern. Then the keyboard knows "it's a sure thing", once it has eliminated the possibility of bounce. The bounce interval selected, should exceed any possible spring time constants. The closest thing to a "bounceless" contact, might be keys with Hall probes and hysteresis. And that would be an expensive keyboard. The keys in that case, use magnetism to indicate their presence. The Hall probe sense a magnet is pressed against it, or not. No contacts to wear out, but the keys themselves can eventually mechanically fail. You can still get 10 million cycles from a membrane keyboard. That's what some of the manufacturers will claim, and there are machines you can use to verify lifetime. We used to have two big machines at work, which used to bash on keyboard-type devices as part of reliability testing. I only got to see those on a walking tour, so never got to ask any questions about why the machines were so big. Paul Paul, thanks for the interesting details. Does your kbd have good 'action', for me that means not having to press the keys too far, or with too much pressure, so a light touch allows faster speed? Did you post the procedure on lifehacker or anywhere? And what did your cost if I may ask? |
#6
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hp elite kbd, keys not working
Mike S wrote:
On 2/12/2017 6:46 PM, Paul wrote: Mike S wrote: I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike Keyboards use a scanning matrix. For example, a chip could have a 7x17 matrix, using 24 pins. One set of pins are sources, the others detect key closures. When a "set" of keys die, they're probably sharing one of those wires. Only if the contacts under a single key fail, would you lose just one key. When you lose a set of keys, that's a problem with a scanning wire or scanning wire input. Keyboards can be N-key rollover, or 2-key lockout. The N-key rollover, uses a diode per crosspoint in the scanning matrix. It helps isolate one switch closure from another, and prevents things such as "ghosting" if three keys are pressed. Not many keyboards spend an extra five bucks to do that. (I built my own keyboard, and included those diodes on each switch position.) As for the wiring pattern of the "matrix", the letter assignments don't have to make a lot of sense. I needed a fair number of feedthru wires on my PCB layout, to allow wiring connections around one another. My home-made PCB didn't have plated vias, so when a signal went from one layer to another, a wire was soldered through a hole, to join the connections together. The scanning matrix is generally high impedance. Some of the scanning wires might have been up around 100K ohms or so. This means, it might not take a lot of dirt or debris to upset it. Maybe this was an attempt to reduce emissions from the keyboard or something. In addition, the scanning process uses "debounce". When the key closes a scanning matrix location, the conductor does not immediately sit flat on the connection point. There tend to be springs in keyboards, flexible materials, and they cause contact bounce. The keyboard only declares "closure", after three keyboard matrix scans in a row, show the same closure pattern. Then the keyboard knows "it's a sure thing", once it has eliminated the possibility of bounce. The bounce interval selected, should exceed any possible spring time constants. The closest thing to a "bounceless" contact, might be keys with Hall probes and hysteresis. And that would be an expensive keyboard. The keys in that case, use magnetism to indicate their presence. The Hall probe sense a magnet is pressed against it, or not. No contacts to wear out, but the keys themselves can eventually mechanically fail. You can still get 10 million cycles from a membrane keyboard. That's what some of the manufacturers will claim, and there are machines you can use to verify lifetime. We used to have two big machines at work, which used to bash on keyboard-type devices as part of reliability testing. I only got to see those on a walking tour, so never got to ask any questions about why the machines were so big. Paul Paul, thanks for the interesting details. Does your kbd have good 'action', for me that means not having to press the keys too far, or with too much pressure, so a light touch allows faster speed? Did you post the procedure on lifehacker or anywhere? And what did your cost if I may ask? This was a long long time ago, back when I was working on my TMS9900 project (yes, the ceramic one with gold plated pins). I actually got this running. Considering the construction techniques, it's a miracle. https://en.wikipedia.org/wiki/Texas_Instruments_TMS9900 The keyboard would be considered "totally irrelevant" to todays computing - no Windows key :-) The basic key matrix was from Jameco. I did a PCB that was at least 12" wide and 6" deep. Copper tracks were drawn with India Ink, etched in ferric chloride, and so on. I didn't even use Photoresist. That was perhaps the largest PCB I ever made by hand. Transferring the drill pattern to the PCB was... interesting. (The layout would be similar to this one... Very basic QUERTY.) http://www.applefritter.com/sites/de...es/fig2-17.jpg The really fun part, is you don't insert the keys into the PCB one at a time. The keys come in a plastic frame, so you have to manipulate the frame as one monolithic unit. You bring the PCB up to the base of the keyboard. Well, guess what ? A hundred-plus springy wires have to be poked into the PCB holes. I used things like a bicycle spoke, to manipulate the legs on the keys and guide them into the holes (one... at... a... time...). It took me around two hours to finally "home" the key matrix, into the PCB. Then solder it into place, so it could not escape :-) That keyboard is still around here somewhere. I've lost track of it. It's the principles I learned while building it, that stuck with me. The keyboard itself never saw a lot of usage. The computer had no software. You hand-assembled code using the instruction set documents. So there wasn't much chance of "doing Notepad" with the thing. It was barely a computer. Also, the concepts have slightly changed since then. Those keyboard encoders only had "key down" codes. If you typed the letter "Q", that byte of data was sent across a parallel ribbon cable, along with a strobe signal. Whereas modern keyboards send "key_down" and "key_up" codes, as a function of whether the key is still depressed or not. The basic functional description remains the same, but some of the details are different. You have a better ability to keep track of what is going on, with the modern keyboard. Paul |
#7
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hp elite kbd, keys not working
"Mike S" wrote in message news
I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike https://www.youtube.com/watch?v=jgP90sO2AKs http://support.hp.com/us-en/product/...yboard/3707817 Clean all the muck out then use switch cleaner, I use Servisol, or isopropyl alcohol to clean pads. Kenny |
#8
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hp elite kbd, keys not working
On 2/13/2017 12:57 AM, Kenny wrote:
"Mike S" wrote in message news I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike https://www.youtube.com/watch?v=jgP90sO2AKs http://support.hp.com/us-en/product/...yboard/3707817 Clean all the muck out then use switch cleaner, I use Servisol, or isopropyl alcohol to clean pads. Kenny Good idea, I'll use isopropyl alcohol, thanks. |
#9
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hp elite kbd, keys not working
On 2/12/2017 8:24 PM, Paul wrote:
Mike S wrote: On 2/12/2017 6:46 PM, Paul wrote: Mike S wrote: I bought an HP elite v2 kbd because it has such great action, it's the fastest kbd I've ever used. After about a year the End key stopped working, today the C, D and E keys stopped working. Does anyone have any experience with these kbds? Do they die off after a year or so? I'm going to take it apart and see if there are any easy fixes, any comments would be interesting to hear. TIA, Mike Keyboards use a scanning matrix. For example, a chip could have a 7x17 matrix, using 24 pins. One set of pins are sources, the others detect key closures. When a "set" of keys die, they're probably sharing one of those wires. Only if the contacts under a single key fail, would you lose just one key. When you lose a set of keys, that's a problem with a scanning wire or scanning wire input. Keyboards can be N-key rollover, or 2-key lockout. The N-key rollover, uses a diode per crosspoint in the scanning matrix. It helps isolate one switch closure from another, and prevents things such as "ghosting" if three keys are pressed. Not many keyboards spend an extra five bucks to do that. (I built my own keyboard, and included those diodes on each switch position.) As for the wiring pattern of the "matrix", the letter assignments don't have to make a lot of sense. I needed a fair number of feedthru wires on my PCB layout, to allow wiring connections around one another. My home-made PCB didn't have plated vias, so when a signal went from one layer to another, a wire was soldered through a hole, to join the connections together. The scanning matrix is generally high impedance. Some of the scanning wires might have been up around 100K ohms or so. This means, it might not take a lot of dirt or debris to upset it. Maybe this was an attempt to reduce emissions from the keyboard or something. In addition, the scanning process uses "debounce". When the key closes a scanning matrix location, the conductor does not immediately sit flat on the connection point. There tend to be springs in keyboards, flexible materials, and they cause contact bounce. The keyboard only declares "closure", after three keyboard matrix scans in a row, show the same closure pattern. Then the keyboard knows "it's a sure thing", once it has eliminated the possibility of bounce. The bounce interval selected, should exceed any possible spring time constants. The closest thing to a "bounceless" contact, might be keys with Hall probes and hysteresis. And that would be an expensive keyboard. The keys in that case, use magnetism to indicate their presence. The Hall probe sense a magnet is pressed against it, or not. No contacts to wear out, but the keys themselves can eventually mechanically fail. You can still get 10 million cycles from a membrane keyboard. That's what some of the manufacturers will claim, and there are machines you can use to verify lifetime. We used to have two big machines at work, which used to bash on keyboard-type devices as part of reliability testing. I only got to see those on a walking tour, so never got to ask any questions about why the machines were so big. Paul Paul, thanks for the interesting details. Does your kbd have good 'action', for me that means not having to press the keys too far, or with too much pressure, so a light touch allows faster speed? Did you post the procedure on lifehacker or anywhere? And what did your cost if I may ask? This was a long long time ago, back when I was working on my TMS9900 project (yes, the ceramic one with gold plated pins). I actually got this running. Considering the construction techniques, it's a miracle. https://en.wikipedia.org/wiki/Texas_Instruments_TMS9900 The keyboard would be considered "totally irrelevant" to todays computing - no Windows key :-) The basic key matrix was from Jameco. I did a PCB that was at least 12" wide and 6" deep. Copper tracks were drawn with India Ink, etched in ferric chloride, and so on. I didn't even use Photoresist. That was perhaps the largest PCB I ever made by hand. Transferring the drill pattern to the PCB was... interesting. (The layout would be similar to this one... Very basic QUERTY.) http://www.applefritter.com/sites/de...es/fig2-17.jpg The really fun part, is you don't insert the keys into the PCB one at a time. The keys come in a plastic frame, so you have to manipulate the frame as one monolithic unit. You bring the PCB up to the base of the keyboard. Well, guess what ? A hundred-plus springy wires have to be poked into the PCB holes. I used things like a bicycle spoke, to manipulate the legs on the keys and guide them into the holes (one... at... a... time...). It took me around two hours to finally "home" the key matrix, into the PCB. Then solder it into place, so it could not escape :-) That keyboard is still around here somewhere. I've lost track of it. It's the principles I learned while building it, that stuck with me. The keyboard itself never saw a lot of usage. The computer had no software. You hand-assembled code using the instruction set documents. So there wasn't much chance of "doing Notepad" with the thing. It was barely a computer. Also, the concepts have slightly changed since then. Those keyboard encoders only had "key down" codes. If you typed the letter "Q", that byte of data was sent across a parallel ribbon cable, along with a strobe signal. Whereas modern keyboards send "key_down" and "key_up" codes, as a function of whether the key is still depressed or not. The basic functional description remains the same, but some of the details are different. You have a better ability to keep track of what is going on, with the modern keyboard. Paul That was an ambitious project. Yes being able to detect the keydown or keyup is useful in programming. |
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