Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
Aron Smith wrote: On Wednesday 06 April 2005 01:10 pm, Philippe Landau wrote: Miark wrote: Try connecting the USB cable _before_ you plug in the external drive's power supply. thanks a lot for all the expertly advice, Joe, Mikkel, Miark and jdow. it looks like the external case is leaking power to USB, because it happens even when its power switch is off, but so far not when i disconnect it from electricity. i will visit my electrician friend and see what he can measure :-) Tell him to look for ground loops Take a multimeter set it on voltage with the mouse unplugged measure between the computer and the external drive case to case if there is *ANY* voltage potential between the two you have an improperly wired power supply most likely on the external drive Get this fixed asap it is dangerous that was excellent advice, thank you, Aron and the other helpers. my friend measured voltage flowing through usb to the ground while the harddisk case was connected but off. i was disappointed to have to pressure the large dealer to let me buy a replacement (a different, slightly more expensive model: maxtor onetouch 2, heavy, unpolished sharp edge, fanless, quiet); he only wanted to ship the case to the manufacturer for repair ... i cited the experts from the mandrake list and succeeded :-) kind regards philippe Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
from your description it would appear you have a grounding problem with your pc, or a defective hard drive. the electric flash as you plug it in (before the system can recognize/initialize it) should not be a control signal per se, but rather is likely extraneous current that improper grounding is letting reach circuitry it shouldn't. On Apr 6, 2005 6:23 AM, Philippe Landau [EMAIL PROTECTED] wrote: when i plug in my new Data-Tec D350U USB 2 external harddisk, i see a small electric flash which can cause my PC to shutdown instantly. i know USB is powered, carrying a small voltage, so the flash is not unexpected. also as it is used to send control signals i can understand that it powers down my PC. but it is risky for my data, so i would like to know if others saw that happen too. kind regards philippe Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
Joe Mecklin wrote: from your description it would appear you have a grounding problem with your pc, or a defective hard drive. the electric flash as you plug it in (before the system can recognize/initialize it) should not be a control signal per se, but rather is likely extraneous current that improper grounding is letting reach circuitry it shouldn't. that is possible. do you connect the case of your PC to the power unit ? could the grounding problem be on the side of the harddisk enclosure ? i really don't understand these simple electrical issues. kind regards philippe -- On Apr 6, 2005 6:23 AM, Philippe Landau [EMAIL PROTECTED] wrote: when i plug in my new Data-Tec D350U USB 2 external harddisk, i see a small electric flash which can cause my PC to shutdown instantly. i know USB is powered, carrying a small voltage, so the flash is not unexpected. also as it is used to send control signals i can understand that it powers down my PC. but it is risky for my data, so i would like to know if others saw that happen too. Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
assuming (i know that's a dangerous practice) the case/motherboard/power supply are all properly designed, the grounding will be builtin such that you really don't have to worry about it, but here are some things to look for: the power supply will have a black wire as part of its wiring harness for each connector; this will be the grounding lead that keeps the power common with the surrounding metal so those flashes are dissipated before they can do damage. about the only things you can check on the motherboard are that the mounting screws are tight/snug, and that all cards/connectors are firmly seated. the case is basically the same as the motherboard in this particular scenario, in that the only things to check are the tightness of the mounting hardware and any connectors to indicator lights/usb/firewire/com/lp/etc plugs. On Apr 6, 2005 7:06 AM, Philippe Landau [EMAIL PROTECTED] wrote: Joe Mecklin wrote: from your description it would appear you have a grounding problem with your pc, or a defective hard drive. the electric flash as you plug it in (before the system can recognize/initialize it) should not be a control signal per se, but rather is likely extraneous current that improper grounding is letting reach circuitry it shouldn't. that is possible. do you connect the case of your PC to the power unit ? could the grounding problem be on the side of the harddisk enclosure ? i really don't understand these simple electrical issues. kind regards philippe -- On Apr 6, 2005 6:23 AM, Philippe Landau [EMAIL PROTECTED] wrote: when i plug in my new Data-Tec D350U USB 2 external harddisk, i see a small electric flash which can cause my PC to shutdown instantly. i know USB is powered, carrying a small voltage, so the flash is not unexpected. also as it is used to send control signals i can understand that it powers down my PC. but it is risky for my data, so i would like to know if others saw that happen too. Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
Philippe Landau wrote: when i plug in my new Data-Tec D350U USB 2 external harddisk, i see a small electric flash which can cause my PC to shutdown instantly. i know USB is powered, carrying a small voltage, so the flash is not unexpected. also as it is used to send control signals i can understand that it powers down my PC. but it is risky for my data, so i would like to know if others saw that happen too. kind regards philippe This sounds more like a static discharge or a bad ground then anything normal. You should not see any flash when you plug in a USB device. The USB connector does have 2 pins for power, but these make connection after the grounded body of the plug is making contact with the USB socket, so even if there were a spark, you would not see it. One thing that can cause problems is if you have a separate power connection for your USB hard drive, and the power supply for it, and the one for the computer, as plugged into different wall outlets. By this, I mean outlets located at different points on the wall, or workbench. If they are on different circuits, and take different paths back to the electrical box, you can end up with different ground levels on the two outlets. The difference is usually not that great, but a 2 volt difference means a lot to computers. The problem is worse if you do not have properly grounded outlets. Mikkel -- Remember: Sometimes the dragon wins! Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
On Wed, 06 Apr 2005 14:23:03 +0200, Philippe wrote: when i plug in my new Data-Tec D350U USB 2 external harddisk, i see a small electric flash which can cause my PC to shutdown instantly. i know USB is powered, carrying a small voltage, so the flash is not unexpected. also as it is used to send control signals i can understand that it powers down my PC. but it is risky for my data, so i would like to know if others saw that happen too. Try connecting the USB cable _before_ you plug in the external drive's power supply. Miark Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
From: Philippe Landau [EMAIL PROTECTED]
when i plug in my new Data-Tec D350U USB 2 external harddisk,
i see a small electric flash which can cause
my PC to shutdown instantly.
i know USB is powered, carrying a small voltage,
so the flash is not unexpected.
also as it is used to send control signals
i can understand that it powers down my PC.
but it is risky for my data,
so i would like to know if others saw that happen too.
kind regards philippe
Did you discharge static electricity before plugging in the USB connector?
The flash is NOT expected. There's not really enough current that should
be drawn to create such a flash.
{^_^}
Want to buy your Pack or Services from MandrakeSoft?
Go to http://www.mandrakestore.com
Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
Miark wrote: Try connecting the USB cable _before_ you plug in the external drive's power supply. thanks a lot for all the expertly advice, Joe, Mikkel, Miark and jdow. it looks like the external case is leaking power to USB, because it happens even when its power switch is off, but so far not when i disconnect it from electricity. i will visit my electrician friend and see what he can measure :-) kind regards philippe Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
Re: [newbie] [OT] usb electric shock while connecting is shutting down computer
On Wednesday 06 April 2005 01:10 pm, Philippe Landau wrote: Miark wrote: Try connecting the USB cable _before_ you plug in the external drive's power supply. thanks a lot for all the expertly advice, Joe, Mikkel, Miark and jdow. it looks like the external case is leaking power to USB, because it happens even when its power switch is off, but so far not when i disconnect it from electricity. i will visit my electrician friend and see what he can measure :-) Tell him to look for ground loops Take a multimeter set it on voltage with the mouse unplugged measure between the computer and the external drive case to case if there is *ANY* voltage potential between the two you have an improperly wired power supply most likely on the external drive Get this fixed asap it is dangerous kind regards philippe Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com Join the Club : http://www.mandrakeclub.com
