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#1
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"BIOS problem" solved
22-9-2014 I started a thead "Subject: how can BIOS boot priority settings
change all by itself??" Today customer had bootproblems again. Message: diskdrive failed. Couldn't believe that because I had fitted a new drive. I booted into the BIOS setup and was baffled when I saw the detected drives. Where I expected the name of the new drive to show up, I saw a string of strange characters. Couldn't believe the drive had died again. Now I decided to open the case and examine the SATA cable. I took off the cable at both ends and reconnected it. After this the PC booted fine again. So those of you who suggested the cause is bad cable connection were right! -- |\ /| | \/ |@rk \../ \/os |
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#2
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"BIOS problem" solved
Hi, Mark.
I took off the cable at both ends and reconnected it. Ah, yes, the old "Pink Pearl" treatment. ;) Shades of the TRS-80! ;^{ Way back in 1978, when we had unexplained glitches, we would unplug cables - usually from edge-cards in those days. Then we would give the edge card connectors the "Pink Pearl" treatment: we would "erase" the film of fine debris from the edge-card teeth using a pencil eraser, with Pink Pearl being the most common brand name for such erasers. Then we would plug the connector back onto the edge card and...problem solved. ;) Often we didn't even need the eraser; just unplug the cable and plug it in again, letting simple friction remove the film. That simple solution still works surprisingly often. ;) RC -- R. C. White, CPA San Marcos, TX Microsoft Windows MVP (2002-2010) Windows Live Mail 2012 (Build 16.4.3528.0331) in Win8.1 Pro with Media Center "Linea Recta" wrote in message ... 22-9-2014 I started a thead "Subject: how can BIOS boot priority settings change all by itself??" Today customer had bootproblems again. Message: diskdrive failed. Couldn't believe that because I had fitted a new drive. I booted into the BIOS setup and was baffled when I saw the detected drives. Where I expected the name of the new drive to show up, I saw a string of strange characters. Couldn't believe the drive had died again. Now I decided to open the case and examine the SATA cable. I took off the cable at both ends and reconnected it. After this the PC booted fine again. So those of you who suggested the cause is bad cable connection were right! -- |\ /| | \/ |@rk \../ \/os |
#3
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"BIOS problem" solved
"R. C. White" wrote in message ... Hi, Mark. I took off the cable at both ends and reconnected it. Ah, yes, the old "Pink Pearl" treatment. ;) Shades of the TRS-80! ;^{ Way back in 1978, when we had unexplained glitches, we would unplug cables - usually from edge-cards in those days. Then we would give the edge card connectors the "Pink Pearl" treatment: we would "erase" the film of fine debris from the edge-card teeth using a pencil eraser, with Pink Pearl being the most common brand name for such erasers. Then we would plug the connector back onto the edge card and...problem solved. ;) Often we didn't even need the eraser; just unplug the cable and plug it in again, letting simple friction remove the film. That simple solution still works surprisingly often. ;) It shouldn't be happening with modern standardised cables. "Linea Recta" wrote in message ... 22-9-2014 I started a thead "Subject: how can BIOS boot priority settings change all by itself??" Today customer had bootproblems again. Message: diskdrive failed. Couldn't believe that because I had fitted a new drive. I booted into the BIOS setup and was baffled when I saw the detected drives. Where I expected the name of the new drive to show up, I saw a string of strange characters. Couldn't believe the drive had died again. Now I decided to open the case and examine the SATA cable. I took off the cable at both ends and reconnected it. After this the PC booted fine again. So those of you who suggested the cause is bad cable connection were right! |
#4
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"BIOS problem" solved
Rod Speed wrote:
"R. C. White" wrote in message ... Hi, Mark. I took off the cable at both ends and reconnected it. Ah, yes, the old "Pink Pearl" treatment. ;) Shades of the TRS-80! ;^{ Way back in 1978, when we had unexplained glitches, we would unplug cables - usually from edge-cards in those days. Then we would give the edge card connectors the "Pink Pearl" treatment: we would "erase" the film of fine debris from the edge-card teeth using a pencil eraser, with Pink Pearl being the most common brand name for such erasers. Then we would plug the connector back onto the edge card and...problem solved. ;) Often we didn't even need the eraser; just unplug the cable and plug it in again, letting simple friction remove the film. That simple solution still works surprisingly often. ;) It shouldn't be happening with modern standardised cables. As I understand it, this is a connector retention problem or a kinked cable problem. First generation cables have absolutely nothing to hold them in place. The connector body didn't provide a compression (interference) fit. SATA cables would regularly fall off, due to vibration. This happened, because the dudes at SATAIO were spending all their time designing the perfect "SATA backplane connectors". That allows disk drives to be plugged into slots in a server. Such as the 24 bay "things" you can get for servers, to hold drives. Those have a SATA backplane in back, and the carefully designed SATA connectors are inside the box. For the desktop, they just decided to "saw that connector in half and send the plans to China". Without even checking whether this was a good fit for desktop systems or not. Later, some of the little people in the industry decided to fix this stuff. So the connector body got deformed a bit, to provide a compression fit. And later, the "metal jaw" thing was added. The metal jaw thing has to be designed, so if the mating member isn't available on the other end, the parts don't conflict. I got a new motherboard with jaw-equipped cable, and it would not fit on my WD branded hard drive. So I had to fall back to the simpler cable (deformed body). Thus, there are at least two retention features available, and sometimes both features are on the same connector. And this is all because the SATAIO committee didn't test their original design before shipping it. (Otherwise, they would have noticed how bad it was.) The contacts are gold on gold, which relies on a "wiping" action rather than the "biting" action of tin on tin. Since the gold is so thin, erasers are no longer recommended for "reconditioning" the contacts. The gold is so thin (10u instead of 50u), there might already be pinholes in the finish. If you must clean such a connector, try isopropyl alcohol and a lint-free cloth. I would not recommend anything stronger than that. The SATA cable should not be bent until it kinks. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. It's more likely to be a problem, if one conductor is kinked and the other one is not. When the cable changes direction, try to make a "rounded corner" in the cable, not a pinch. I'm still waiting to see an eye diagram or a TDR picture of a kinked cable, to see just how bad bending them is. And use some care when disconnecting a cable from a motherboard. There was one brand of motherboard, with vertical connectors, where the manufacturer didn't affix the connector body to the board very well. A user would tug on the cable, and pull the connector right out of the motherboard. Later connectors were fastened a bit more securely than that. Paul |
#5
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"BIOS problem" solved
"Paul" schreef in bericht
... Rod Speed wrote: "R. C. White" wrote in message ... Hi, Mark. I took off the cable at both ends and reconnected it. Ah, yes, the old "Pink Pearl" treatment. ;) Shades of the TRS-80! ;^{ Way back in 1978, when we had unexplained glitches, we would unplug cables - usually from edge-cards in those days. Then we would give the edge card connectors the "Pink Pearl" treatment: we would "erase" the film of fine debris from the edge-card teeth using a pencil eraser, with Pink Pearl being the most common brand name for such erasers. Then we would plug the connector back onto the edge card and...problem solved. ;) Often we didn't even need the eraser; just unplug the cable and plug it in again, letting simple friction remove the film. That simple solution still works surprisingly often. ;) It shouldn't be happening with modern standardised cables. As I understand it, this is a connector retention problem or a kinked cable problem. First generation cables have absolutely nothing to hold them in place. The connector body didn't provide a compression (interference) fit. SATA cables would regularly fall off, due to vibration. This happened, because the dudes at SATAIO were spending all their time designing the perfect "SATA backplane connectors". That allows disk drives to be plugged into slots in a server. Such as the 24 bay "things" you can get for servers, to hold drives. Those have a SATA backplane in back, and the carefully designed SATA connectors are inside the box. For the desktop, they just decided to "saw that connector in half and send the plans to China". Without even checking whether this was a good fit for desktop systems or not. Later, some of the little people in the industry decided to fix this stuff. So the connector body got deformed a bit, to provide a compression fit. And later, the "metal jaw" thing was added. The metal jaw thing has to be designed, so if the mating member isn't available on the other end, the parts don't conflict. I got a new motherboard with jaw-equipped cable, and it would not fit on my WD branded hard drive. So I had to fall back to the simpler cable (deformed body). Thus, there are at least two retention features available, and sometimes both features are on the same connector. And this is all because the SATAIO committee didn't test their original design before shipping it. (Otherwise, they would have noticed how bad it was.) The contacts are gold on gold, which relies on a "wiping" action rather than the "biting" action of tin on tin. Since the gold is so thin, erasers are no longer recommended for "reconditioning" the contacts. The gold is so thin (10u instead of 50u), there might already be pinholes in the finish. If you must clean such a connector, try isopropyl alcohol and a lint-free cloth. I would not recommend anything stronger than that. Is that what's sold as 'contact cleaner'? The SATA cable should not be bent until it kinks. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. It's more likely to be a problem, if one conductor is kinked and the other one is not. When the cable changes direction, try to make a "rounded corner" in the cable, not a pinch. I'm still waiting to see an eye diagram or a TDR picture of a kinked cable, to see just how bad bending them is. And use some care when disconnecting a cable from a motherboard. There was one brand of motherboard, with vertical connectors, where the manufacturer didn't affix the connector body to the board very well. A user would tug on the cable, and pull the connector right out of the motherboard. Later connectors were fastened a bit more securely than that. thanks for your historical overview. As I wrote, the MB and cable aren't exactly new. Do you have links to pictures of the connector types you mentioned above? I understand they are not exactly compatible? For the moment this computer boots OK, but I'm still thinking about getting a new cable and I don't want to buy the wrong type. The MB is SATA II, and I believe nowadays the standard is SATA III, if that makes any phisical difference. BTW I never pull at the cables, I always pull the connector itself. There are no sharp bends in the cable, but I suppose that's no guarantee that there isn't any invisible micro crack somwhere in the cable. -- |\ /| | \/ |@rk \../ \/os |
#6
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"BIOS problem" solved
"Paul" wrote in message ... Rod Speed wrote: "R. C. White" wrote in message ... Hi, Mark. I took off the cable at both ends and reconnected it. Ah, yes, the old "Pink Pearl" treatment. ;) Shades of the TRS-80! ;^{ Way back in 1978, when we had unexplained glitches, we would unplug cables - usually from edge-cards in those days. Then we would give the edge card connectors the "Pink Pearl" treatment: we would "erase" the film of fine debris from the edge-card teeth using a pencil eraser, with Pink Pearl being the most common brand name for such erasers. Then we would plug the connector back onto the edge card and...problem solved. ;) Often we didn't even need the eraser; just unplug the cable and plug it in again, letting simple friction remove the film. That simple solution still works surprisingly often. ;) It shouldn't be happening with modern standardised cables. As I understand it, this is a connector retention problem Yes, normally, particularly early on. or a kinked cable problem. Hardly ever. First generation cables have absolutely nothing to hold them in place. The connector body didn't provide a compression (interference) fit. SATA cables would regularly fall off, due to vibration. Or due to someone poking around in the case. This happened, because the dudes at SATAIO were spending all their time designing the perfect "SATA backplane connectors". Not really. Clearly that problem was fixable and was fixed. That allows disk drives to be plugged into slots in a server. Such as the 24 bay "things" you can get for servers, to hold drives. Those have a SATA backplane in back, and the carefully designed SATA connectors are inside the box. For the desktop, they just decided to "saw that connector in half and send the plans to China". Without even checking whether this was a good fit for desktop systems or not. That isnt what happened. Later, some of the little people in the industry decided to fix this stuff. So the connector body got deformed a bit, to provide a compression fit. And later, the "metal jaw" thing was added. The metal jaw thing has to be designed, so if the mating member isn't available on the other end, the parts don't conflict. I got a new motherboard with jaw-equipped cable, and it would not fit on my WD branded hard drive. I've never had a problem with my samsungs. So I had to fall back to the simpler cable (deformed body). Thus, there are at least two retention features available, and sometimes both features are on the same connector. And this is all because the SATAIO committee didn't test their original design before shipping it. (Otherwise, they would have noticed how bad it was.) The contacts are gold on gold, which relies on a "wiping" action rather than the "biting" action of tin on tin. Since the gold is so thin, erasers are no longer recommended for "reconditioning" the contacts. The gold is so thin (10u instead of 50u), there might already be pinholes in the finish. If you must clean such a connector, You shouldn't need to. try isopropyl alcohol and a lint-free cloth. I would not recommend anything stronger than that. Any of the small molecular weight alcohols are fine. The SATA cable should not be bent until it kinks. That's true of any signal cable like that. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. Cable impedance just isnt a problem with digital signals. It's more likely to be a problem, if one conductor is kinked and the other one is not. When the cable changes direction, try to make a "rounded corner" in the cable, not a pinch. I'm still waiting to see an eye diagram or a TDR picture of a kinked cable, to see just how bad bending them is. Its not normally a problem, they just don't get kinked that much. And use some care when disconnecting a cable from a motherboard. There was one brand of motherboard, with vertical connectors, where the manufacturer didn't affix the connector body to the board very well. A user would tug on the cable, and pull the connector right out of the motherboard. Later connectors were fastened a bit more securely than that. A lot more securely in fact. |
#7
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"BIOS problem" solved
"Linea Recta" wrote in message ... "Paul" schreef in bericht ... Rod Speed wrote: "R. C. White" wrote in message ... Hi, Mark. I took off the cable at both ends and reconnected it. Ah, yes, the old "Pink Pearl" treatment. ;) Shades of the TRS-80! ;^{ Way back in 1978, when we had unexplained glitches, we would unplug cables - usually from edge-cards in those days. Then we would give the edge card connectors the "Pink Pearl" treatment: we would "erase" the film of fine debris from the edge-card teeth using a pencil eraser, with Pink Pearl being the most common brand name for such erasers. Then we would plug the connector back onto the edge card and...problem solved. ;) Often we didn't even need the eraser; just unplug the cable and plug it in again, letting simple friction remove the film. That simple solution still works surprisingly often. ;) It shouldn't be happening with modern standardised cables. As I understand it, this is a connector retention problem or a kinked cable problem. First generation cables have absolutely nothing to hold them in place. The connector body didn't provide a compression (interference) fit. SATA cables would regularly fall off, due to vibration. This happened, because the dudes at SATAIO were spending all their time designing the perfect "SATA backplane connectors". That allows disk drives to be plugged into slots in a server. Such as the 24 bay "things" you can get for servers, to hold drives. Those have a SATA backplane in back, and the carefully designed SATA connectors are inside the box. For the desktop, they just decided to "saw that connector in half and send the plans to China". Without even checking whether this was a good fit for desktop systems or not. Later, some of the little people in the industry decided to fix this stuff. So the connector body got deformed a bit, to provide a compression fit. And later, the "metal jaw" thing was added. The metal jaw thing has to be designed, so if the mating member isn't available on the other end, the parts don't conflict. I got a new motherboard with jaw-equipped cable, and it would not fit on my WD branded hard drive. So I had to fall back to the simpler cable (deformed body). Thus, there are at least two retention features available, and sometimes both features are on the same connector. And this is all because the SATAIO committee didn't test their original design before shipping it. (Otherwise, they would have noticed how bad it was.) The contacts are gold on gold, which relies on a "wiping" action rather than the "biting" action of tin on tin. Since the gold is so thin, erasers are no longer recommended for "reconditioning" the contacts. The gold is so thin (10u instead of 50u), there might already be pinholes in the finish. If you must clean such a connector, try isopropyl alcohol and a lint-free cloth. I would not recommend anything stronger than that. Is that what's sold as 'contact cleaner'? That varys, but often is. The SATA cable should not be bent until it kinks. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. It's more likely to be a problem, if one conductor is kinked and the other one is not. When the cable changes direction, try to make a "rounded corner" in the cable, not a pinch. I'm still waiting to see an eye diagram or a TDR picture of a kinked cable, to see just how bad bending them is. And use some care when disconnecting a cable from a motherboard. There was one brand of motherboard, with vertical connectors, where the manufacturer didn't affix the connector body to the board very well. A user would tug on the cable, and pull the connector right out of the motherboard. Later connectors were fastened a bit more securely than that. thanks for your historical overview. As I wrote, the MB and cable aren't exactly new. Do you have links to pictures of the connector types you mentioned above? I understand they are not exactly compatible? They are with decent hard drives. For the moment this computer boots OK, but I'm still thinking about getting a new cable and I don't want to buy the wrong type. They arent that expensive, get more than one and try it. The MB is SATA II, and I believe nowadays the standard is SATA III, if that makes any phisical difference. No it does not with the connector. BTW I never pull at the cables, I always pull the connector itself. Yeah, that's important. There are no sharp bends in the cable, but I suppose that's no guarantee that there isn't any invisible micro crack somwhere in the cable. That's quite uncommon due to the physics of the cables. |
#8
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"BIOS problem" solved
In message , Rod Speed
writes: [] I've never had a problem with my samsungs. Sounds painful! [] Any of the small molecular weight alcohols are fine. The SATA cable should not be bent until it kinks. That's true of any signal cable like that. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. Cable impedance just isnt a problem with digital signals. If it wasn't, you wouldn't be worrying about kinks above. It's an analogue world - especially at the sort of frequencies we work at these days. But even back in the days of 10 megabit ethernet, impedance was relevant (75 ohm coax, IIRR). That's why, ideally, you had terminators. [] -- J. P. Gilliver. UMRA: 1960/1985 MB++G()AL-IS-Ch++(p)Ar@T+H+Sh0!:`)DNAf All humanity is divided into three classes: those who are immovable, those who are movable, and those who move! - Benjamin Franklin |
#9
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"BIOS problem" solved
Linea Recta wrote:
thanks for your historical overview. As I wrote, the MB and cable aren't exactly new. Do you have links to pictures of the connector types you mentioned above? I understand they are not exactly compatible? For the moment this computer boots OK, but I'm still thinking about getting a new cable and I don't want to buy the wrong type. The MB is SATA II, and I believe nowadays the standard is SATA III, if that makes any phisical difference. BTW I never pull at the cables, I always pull the connector itself. There are no sharp bends in the cable, but I suppose that's no guarantee that there isn't any invisible micro crack somwhere in the cable. Here is a picture summary. http://i59.tinypic.com/2vbrjns.jpg The Western Digital drive in the lower right hand corner, the connector still fits. But the metal "latch" feature has nothing to engage on, on the WD drive. This is because the WD drive has extra clearance between the housing and the connector tabs. The cable still grips a bit, but doesn't have quite the interference fit of the red colored cable. The red colored cable, only the distortion of the connector body holds the connector in place. And some of those red cables, press a little too tight. Using compression as a method, relies on tight tolerances when molding the connectors. I have a set of cables here, which pressed so tight, plastic gets scraped off the cable connector body on each usage. You may find some motherboard connector, that doesn't like the metal-work on a fancy modern cable. I don't have a large enough collection of computer crap, to give examples. You can use the connectors with the metal latches. And some motherboard connectors mate nicely with the metal latch. But I've discovered at least one hard drive here, where the metal latch "tooth" has nothing to grab onto. The cable still stays in place, because the connector body is still an interference fit. Just not a super-tight one. One of the reasons the back of the WD drive is so goofy looking, is WD attempted to market their own cable assembly. It consisted of a monolithic "block" with both power and signal in the same connector. As well as a "square part" that fits in the square hole in the WD drive housing. So that's the history of how the WD drive housing ended up that way. It was to help WD sell their cable assembly. The sample Seagate drive in my picture, is just designed for the more average cabling. Seagate didn't try to sell a special looking cable. The Secure Connect was WD's answer to the first gen cables falling off. It's an inventive solution, but I bet WD wishes they hadn't done that now. I don't expect they made that much money on the cables. "Western Digital Secure Connect cable" http://www.legitreviews.com/images/r...al_secure3.jpg Paul |
#10
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"BIOS problem" solved
J. P. Gilliver (John) wrote:
In message , Rod Speed writes: [] I've never had a problem with my samsungs. Sounds painful! [] Any of the small molecular weight alcohols are fine. The SATA cable should not be bent until it kinks. That's true of any signal cable like that. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. Cable impedance just isnt a problem with digital signals. If it wasn't, you wouldn't be worrying about kinks above. It's an analogue world - especially at the sort of frequencies we work at these days. But even back in the days of 10 megabit ethernet, impedance was relevant (75 ohm coax, IIRR). That's why, ideally, you had terminators. [] OK, here's a couple waveforms. The smooth one is what the unbent cable will look like. The one with ringback, would be when the cable is kinked. Try as I might, including the word "SATA" in my Googling, does not dig up actual SATA waveforms for me to post. So I have to make do with whatever waveforms I can find. http://ts4.mm.bing.net/th?id=HN.6080...5&pid=15.1&P=0 http://www.micron.com/-/media/images...d_data_eye.png That's the kind of measurements I'd want to see, if bending the cable and studying what kind of a difference it makes. The smooth waveform in those examples, shows the pulse template on the screen at the same time as the waveform. The dark blue diamond in the center, checks eye closure. The top and bottom blue rectangles check for overshoot. The waveform is automatically normalized to fit in the scope window (so you don't have to adjust the gain and offset knobs on the scope). The pulse template is met by TX and RX designers, and is an "agreement" as to what their end has to do, in order to work. So you check your design (disk drive or motherboard), to see if it is making the right quality of waveform. If the waveform touches the template, it doesn't mean "instant death". But if two marginal pieces of equipment get connected together, the room is hot, the +5V voltage feeding the equipment is low, there might be transmission errors. Passing the template means you have some margin against conditions like that. I would want to see the kinked cable tested, to see how much waveform distortion results from kinking one of the two conductors. Kinking both of them the same amount, while it degrades the waveform, might not be as effective as kinking just one conductor. The SATA cable is a miniature dual twinax (one pair for serial TX, one pair for RX). And when I say "kink", I'm referring to the compression of the shield around one of the two conductors in that pair. The twinax conductors are differentially terminated at the receiver, in 100 ohms or so. (SATA cable cross-section) http://www.satacables.com/assets/images/IMG_188353.jpg Paul |
#11
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"BIOS problem" solved
J. P. Gilliver (John) wrote
Rod Speed wrote I've never had a problem with my samsungs. Sounds painful! Nope, completely painless. Any of the small molecular weight alcohols are fine. The SATA cable should not be bent until it kinks. That's true of any signal cable like that. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. Cable impedance just isnt a problem with digital signals. If it wasn't, you wouldn't be worrying about kinks above. I don't worry about kinks above. It's an analogue world Nope. - especially at the sort of frequencies we work at these days. Not in the sense that the cable impedance matters. But even back in the days of 10 megabit ethernet, impedance was relevant (75 ohm coax, IIRR). That's why, ideally, you had terminators. But PATA didn't and SATA doesn't either. |
#12
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"BIOS problem" solved
Paul wrote
J. P. Gilliver (John) wrote Rod Speed wrote The SATA cable should not be bent until it kinks. That's true of any signal cable like that. This has an impact on the dielectric insulation inside the cable. And can change the cable impedance. Cable impedance just isnt a problem with digital signals. If it wasn't, you wouldn't be worrying about kinks above. It's an analogue world - especially at the sort of frequencies we work at these days. But even back in the days of 10 megabit ethernet, impedance was relevant (75 ohm coax, IIRR). That's why, ideally, you had terminators. OK, here's a couple waveforms. The smooth one is what the unbent cable will look like. The one with ringback, would be when the cable is kinked. Not with SATA. Try as I might, including the word "SATA" in my Googling, does not dig up actual SATA waveforms for me to post. Because cable kinking isnt a problem with SATA. So I have to make do with whatever waveforms I can find. http://ts4.mm.bing.net/th?id=HN.6080...5&pid=15.1&P=0 http://www.micron.com/-/media/images...d_data_eye.png Those arent relevant to SATA. That's the kind of measurements I'd want to see, if bending the cable and studying what kind of a difference it makes. It clearly doesn't if you can't turn them up with google. The smooth waveform in those examples, shows the pulse template on the screen at the same time as the waveform. The dark blue diamond in the center, checks eye closure. The top and bottom blue rectangles check for overshoot. The waveform is automatically normalized to fit in the scope window (so you don't have to adjust the gain and offset knobs on the scope). The pulse template is met by TX and RX designers, and is an "agreement" as to what their end has to do, in order to work. So you check your design (disk drive or motherboard), to see if it is making the right quality of waveform. No point with SATA. If the waveform touches the template, it doesn't mean "instant death". But if two marginal pieces of equipment get connected together, the room is hot, the +5V voltage feeding the equipment is low, there might be transmission errors. Not with SATA. Passing the template means you have some margin against conditions like that. And that is what SATA ensures. I would want to see the kinked cable tested, to see how much waveform distortion results from kinking one of the two conductors. That isnt going to happen with a SATA cable. Kinking both of them the same amount, while it degrades the waveform, might not be as effective as kinking just one conductor. And is what happens with a SATA cable. The SATA cable is a miniature dual twinax (one pair for serial TX, one pair for RX). And when I say "kink", I'm referring to the compression of the shield around one of the two conductors in that pair. That isnt going to happen with a SATA cable. The twinax conductors are differentially terminated at the receiver, in 100 ohms or so. (SATA cable cross-section) http://www.satacables.com/assets/images/IMG_188353.jpg |
#13
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"BIOS problem" solved
Rod Speed wrote:
That isnt going to happen with a SATA cable. Thanks for providing the incentive for me to keep searching. http://h20566.www2.hp.com/portal/sit...4892.199480143 "Never bend a SATA data cable tighter than a 30 mm (1.18 in) radius. Never crease a SATA data cable." Notice that SATA power cables are not mentioned. This is because SATA power cables are not coaxial or twinaxial in nature, and there is no AC impedance to worry about in that respect. A SATA Power cable should not be bent so tightly as to break the copper wire inside. Paul |
#14
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"BIOS problem" solved
Paul wrote
Rod Speed wrote Paul wrote The SATA cable is a miniature dual twinax (one pair for serial TX, one pair for RX). And when I say "kink", I'm referring to the compression of the shield around one of the two conductors in that pair. That isnt going to happen with a SATA cable. Thanks for providing the incentive for me to keep searching. http://h20566.www2.hp.com/portal/sit...4892.199480143 "Never bend a SATA data cable tighter than a 30 mm (1.18 in) radius. Never crease a SATA data cable." That isnt for the reason you were talking about. Notice that SATA power cables are not mentioned. This is because SATA power cables are not coaxial or twinaxial in nature, and there is no AC impedance to worry about in that respect. A SATA Power cable should not be bent so tightly as to break the copper wire inside. |
#15
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"BIOS problem" solved
On Thu, 06 Nov 2014 05:34:42 -0500, Paul wrote:
Rod Speed wrote: That isnt going to happen with a SATA cable. Thanks for providing the incentive for me to keep searching. http://h20566.www2.hp.com/portal/sit...4892.199480143 "Never bend a SATA data cable tighter than a 30 mm (1.18 in) radius. Never crease a SATA data cable." Notice that SATA power cables are not mentioned. This is because SATA power cables are not coaxial or twinaxial in nature, and there is no AC impedance to worry about in that respect. A SATA Power cable should not be bent so tightly as to break the copper wire inside. Paul Apropos of nothing (although I offer thanks for being motivated to look further above!), I still remember as a child not understanding how electricity could still get to the light bulb when there was a knot in the wire. Although some here might think otherwise, by "child" I mean when I was a kid of 4 years of age, not when I was 19 years old. -- Gene E. Bloch (Stumbling Bloch) |
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