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#46
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USB device shuts down PC
w_tom wrote:
On May 21, 1:35 am, Paul wrote: If +5VSB is ever "flattened", that can cause the power supply to go off. The question is, what is the mechanism - badly designed motherboard, badly designed USB device (spec violation on insertion), or whatever. A simplemultimeteris not going to do a good job of highlighting a transient problem. The transient could be quite short. A transient that short would never cause a problematic voltage reduction. And increases wire would not avert that transient. However the extension cord may cause a USB device to not enter High Speed mode. +5VSB must be so low as to be defective even without the USB device. Would still boot the computer. Would appear defective only on the multimeter. So close to the edge that a USB device in High Speed mode finally causes the crash. There exists a wide area between good voltage and a crashed computer. In that wide region is a working computer and a voltage too low. A condtion found using a multimeter. Again, a USB transient cannot be that fast and still crash a computer. Extension cord wire cannot diminish that current. At least half the posts here are immediately eliminated if simply measuring the +5VSB with a multimeter. Without those voltage numbers, we are doing nothing but wild speculation. I believe that that you are incorrect. I have experienced the 'puter shutting down because of a static charge when I plugged a a USB drive in. The solution to my problem was as simple as raising the humidity to about 25%. Have not had any problems since. John |
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#47
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USB device shuts down PC
w_tom wrote:
On May 21, 1:35 am, Paul wrote: If +5VSB is ever "flattened", that can cause the power supply to go off. The question is, what is the mechanism - badly designed motherboard, badly designed USB device (spec violation on insertion), or whatever. A simplemultimeteris not going to do a good job of highlighting a transient problem. The transient could be quite short. A transient that short would never cause a problematic voltage reduction. And increases wire would not avert that transient. However the extension cord may cause a USB device to not enter High Speed mode. +5VSB must be so low as to be defective even without the USB device. Would still boot the computer. Would appear defective only on the multimeter. So close to the edge that a USB device in High Speed mode finally causes the crash. There exists a wide area between good voltage and a crashed computer. In that wide region is a working computer and a voltage too low. A condtion found using a multimeter. Again, a USB transient cannot be that fast and still crash a computer. Extension cord wire cannot diminish that current. At least half the posts here are immediately eliminated if simply measuring the +5VSB with a multimeter. Without those voltage numbers, we are doing nothing but wild speculation. I believe that that you are incorrect. I have experienced the 'puter shutting down because of a static charge when I plugged a a USB drive in. The solution to my problem was as simple as raising the humidity to about 25%. Have not had any problems since. John |
#48
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USB device shuts down PC
On May 23, 4:47*pm, john wrote:
I believe that that you are incorrect. *I have experienced the 'puter shutting down because of a static charge when I plugged a a USB drive in. *The solution to my problem was as simple as raising the humidity to about 25%. *Have not had any problems since. The previous post was about load. If a USB load can cause a PC shutdown, the defective voltage is obvious with numbers from a multimeter even when the computer is loaded and not causing a shutdown. Transients such as a static electric discharge must be so large as to be obvious by sight or even feel. One reason is because of the filtering required on every USB port (and that might be missing on a discounted USB port). I have even seen static electricity eventually cause damage to the USB device and still not crash the computer. IOW is a static discharge is causing a computer crash, well, first the filtering (and how chassis ground connected differently from digital power ground) would explain that failure. One test of any computer is to put it on a glass table (because wood and other materials are much too electrically conductive). Then build up major static electricity and touch various corners of the computer. Some computers are so poorly constructed (either motherboard connects to the chassis at too many points) as to crash when that static electric discharged occurs to the chassis. So yes, static electric discharge can crash a computer. But only if the computer is improperly assembled so that static electric discharges into the digital (power) ground. Again, posted was a response to a USB load created crash. Not a 'static electric discharge' created crash. Due to filtering, that discharge still should not crash the computer. And that discharge should be obvious to create a crash if the different grounds are improperly implemented. |
#49
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USB device shuts down PC
On May 23, 4:47*pm, john wrote:
I believe that that you are incorrect. *I have experienced the 'puter shutting down because of a static charge when I plugged a a USB drive in. *The solution to my problem was as simple as raising the humidity to about 25%. *Have not had any problems since. The previous post was about load. If a USB load can cause a PC shutdown, the defective voltage is obvious with numbers from a multimeter even when the computer is loaded and not causing a shutdown. Transients such as a static electric discharge must be so large as to be obvious by sight or even feel. One reason is because of the filtering required on every USB port (and that might be missing on a discounted USB port). I have even seen static electricity eventually cause damage to the USB device and still not crash the computer. IOW is a static discharge is causing a computer crash, well, first the filtering (and how chassis ground connected differently from digital power ground) would explain that failure. One test of any computer is to put it on a glass table (because wood and other materials are much too electrically conductive). Then build up major static electricity and touch various corners of the computer. Some computers are so poorly constructed (either motherboard connects to the chassis at too many points) as to crash when that static electric discharged occurs to the chassis. So yes, static electric discharge can crash a computer. But only if the computer is improperly assembled so that static electric discharges into the digital (power) ground. Again, posted was a response to a USB load created crash. Not a 'static electric discharge' created crash. Due to filtering, that discharge still should not crash the computer. And that discharge should be obvious to create a crash if the different grounds are improperly implemented. |
#50
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USB device shuts down PC
On May 23, 6:56*am, Leythos wrote:
And you can't measure that value without cutting into the cable/device, since you have to measure it at the device to be sure. Anyone with first year technician education knows wire need not be cut to measure. It says so much about that poster's knowledge. He only understands swapping parts - shotgunning. Does not even know how to use a meter. Multimeters are required even by every auto mechanic because a meter is that easy necessary for fixing things electrical. But the technically ignorant - shotgunners - never learn how to use the meter. Even assume a wire must be cut to measure. A defective power supply can still boot a computer. The most technically ignorant see that computer boot and then magically *know * a defective supply must be good. A shotgunner who never learned would not even know how to use the meter and post lies to deny that technical ignorance. |
#51
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USB device shuts down PC
On May 23, 6:56*am, Leythos wrote:
And you can't measure that value without cutting into the cable/device, since you have to measure it at the device to be sure. Anyone with first year technician education knows wire need not be cut to measure. It says so much about that poster's knowledge. He only understands swapping parts - shotgunning. Does not even know how to use a meter. Multimeters are required even by every auto mechanic because a meter is that easy necessary for fixing things electrical. But the technically ignorant - shotgunners - never learn how to use the meter. Even assume a wire must be cut to measure. A defective power supply can still boot a computer. The most technically ignorant see that computer boot and then magically *know * a defective supply must be good. A shotgunner who never learned would not even know how to use the meter and post lies to deny that technical ignorance. |
#53
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USB device shuts down PC
In article 0143fd5d-c39d-4cfd-9cac-0ed0625e8954
@s28g2000vbp.googlegroups.com, says... On May 23, 6:56*am, Leythos wrote: And you can't measure that value without cutting into the cable/device, since you have to measure it at the device to be sure. Anyone with first year technician education knows wire need not be cut to measure. It says so much about that poster's knowledge. Anyone with basic knowledge, which you don't have, knows that you can't measure without reaching a conductor - since the USB device is connected via a cable (at least what was beind discussed), there are NO EXPOSED CONDUCTORS - cutting into the CABLE is necessary in order to expose a conductor - you said "wire", I said "cable", they are not the same. He only understands swapping parts - shotgunning. Does not even know how to use a meter. Multimeters are required even by every auto mechanic because a meter is that easy necessary for fixing things electrical. But the technically ignorant - shotgunners - never learn how to use the meter. Even assume a wire must be cut to measure. You said "Wire" and I said "Cable", showing that you are a idiot. If you don't cut into the USB "CABLE" to expose the "Wire" (notice I didn't say cut the WIRE), then you can't measure the voltage AT THE DEVICE. Please explain to the OP how he's going to measure a value at the Device side when it's connected via a USB cable if he can't reach any conductors to measure at? -- - Igitur qui desiderat pacem, praeparet bellum. - Calling an illegal alien an "undocumented worker" is like calling a drug dealer an "unlicensed pharmacist" (remove 999 for proper email address) |
#54
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USB device shuts down PC
Thanks for all the replies
Recently changed the PSU and the problem stuill exists. Is this now a motherboard fault? Thanks "bg" wrote: Neil wrote in message ... Hi, I have a PC running Windows XP home. I have both front & rear USB ports. If I plug a printer into any of the USB ports, the PC shuts down with out warning. If I plug a USB memory stick into any of the ports, the same thing happens. I have a USB extension lead, if I plug the extension lead into any USB port and then plug the memory stick into the extension it works OK. I have recently installed a PCI USB card, the computer still shuts down when devices are plugged in. Any suggestions? Thank you. I recently added a few USB connectors and had the same problem. I assumed that something was shorting during the insertion, so I changed the connectors and the problem went away. Seeing as your extension cable works, you might want to do the same. bg |
#55
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USB device shuts down PC
Thanks for all the replies
Recently changed the PSU and the problem stuill exists. Is this now a motherboard fault? Thanks "bg" wrote: Neil wrote in message ... Hi, I have a PC running Windows XP home. I have both front & rear USB ports. If I plug a printer into any of the USB ports, the PC shuts down with out warning. If I plug a USB memory stick into any of the ports, the same thing happens. I have a USB extension lead, if I plug the extension lead into any USB port and then plug the memory stick into the extension it works OK. I have recently installed a PCI USB card, the computer still shuts down when devices are plugged in. Any suggestions? Thank you. I recently added a few USB connectors and had the same problem. I assumed that something was shorting during the insertion, so I changed the connectors and the problem went away. Seeing as your extension cable works, you might want to do the same. bg |
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