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#1
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Insufficient current over USB ports
I just discovered that the USB ports on my Asus M3N78-PRO motherboard
are not supplying sufficient current. The result: power-demanding USB devices like a Canon USB 2.0 scanner and an iPod Touch 3 would appear then disappear then appear then ... in the device list. Isn't there a USB 2.0 standard for motherboard designers and manufacturers to follow? Or is it my Antec TruePower New 650W power supply? -- @~@ You have the right to remain silence. / v \ Simplicity is Beauty! May the Force and farces be with you! /( _ )\ (Fedora 15 i686) Linux 3.0.4 ^ ^ 22:56:01 up 5 days 2:09 0 users load average: 0.09 0.05 0.06 不借貸! 不詐騙! 不援交! 不打交! 不打劫! 不自殺! 請考慮綜援 (CSSA): http://www.swd.gov.hk/tc/index/site_...sub_addressesa |
#2
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Insufficient current over USB ports
On 17/10/2011 11:58 PM, Man-wai Chang wrote:
I just discovered that the USB ports on my Asus M3N78-PRO motherboard are not supplying sufficient current. The result: power-demanding USB devices like a Canon USB 2.0 scanner and an iPod Touch 3 would appear then disappear then appear then ... in the device list. Isn't there a USB 2.0 standard for motherboard designers and manufacturers to follow? Or is it my Antec TruePower New 650W power supply? Easy solution ... just get a PCI USB card and install it. They usually have more power available than onboard USB. I plug one of these cards into all my computers no matter how many onboard USB ports the motherboard has. Far cheaper to pop a chip off a card than it is to pop a chip off a motherboard. Did that recently to the onboard USB hub in my Mac keyboard. When I dismantled the keyboard, the USB chip had exploded. A bit too much current draw! -- Krypsis |
#3
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Insufficient current over USB ports
Man-wai Chang wrote:
I just discovered that the USB ports on my Asus M3N78-PRO motherboard are not supplying sufficient current. The result: power-demanding USB devices like a Canon USB 2.0 scanner and an iPod Touch 3 would appear then disappear then appear then ... in the device list. Isn't there a USB 2.0 standard for motherboard designers and manufacturers to follow? Or is it my Antec TruePower New 650W power supply? At one time, Asus motherboards had "USBPWR" jumpers, to select power source. The options were +5V or +5VSB, as the powering rail. You would use +5VSB, if the USB port connected to that jumper, was to be used to "wake" the computer. For example, if you wanted to "wake on keyboard", you'd set the jumper to +5VSB. Recent motherboards, don't have those jumpers any more. You may find, that the USB ports are powered by +5VSB. The power supply label, has a current rating for +5VSB. It can be on the order of 2 amps to 3 amps. If the motherboard uses 1 amp for things like standby current for LAN or the like, that may leave 1 amp minimum remaining for USB. A USB2 device, can draw up to 500mA. If you have two of the heavier loading USB2 devices, that would be 1 ampere total. At the USB ports themselves, they're arranged in pairs. The Asus motherboard may have one Polyfuse, connected to the two USB devices in a "stack of two" connectors. The rating of the fuse is printed on top. I've got some motherboards here, where I see "1.1" printed on the green Polyfuse. If two 500mA devices are connected, I presume the automatic fuse won't open. I've seen suggestions, that the USB stack not be "policed" by that fuse, and the fuse is supposed to be set a bit higher, as a means of hardware protection, rather than policing the current draw to exactly 2x500mA = 1 ampere. I can't say in your case, which of those mechanisms would be at work. As Krypsis says, a USB2 PCI card, is an easy way to modify the power distribution. As long as the USB2 PCI card draws power from +5V for the ports, then you'd end up using a different rail on the power supply. Some USB2 cards, have an "Aux" power connector on the end of the card, which implies powering from +5V (just a guess). If the card costs $10, and you have a free PCI slot in the system, it's worth a try. Paul |
#4
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Insufficient current over USB ports
Easy solution ... just get a PCI USB card and install it. They usually
have more power available than onboard USB. I plug one of these cards into all my computers no matter how many onboard USB ports the motherboard has. Far cheaper to pop a chip off a card than it is to pop a chip off a motherboard. Did that recently to the onboard USB hub in my Mac keyboard. When I dismantled the keyboard, the USB chip had exploded. A bit too much current draw! Right now I am using a powered USB hub. I think another good solution is to buy a POWERED PCIe USB 3 adaptor. Anyway, I plan to upgrade my motherboard to one that has USB 3.0 ports. -- @~@ You have the right to remain silence. / v \ Simplicity is Beauty! May the Force and farces be with you! /( _ )\ (Fedora 15 i686) Linux 3.0.4 ^ ^ 22:56:01 up 5 days 2:09 0 users load average: 0.09 0.05 0.06 不借貸! 不詐騙! 不援交! 不打交! 不打劫! 不自殺! 請考慮綜援 (CSSA): http://www.swd.gov.hk/tc/index/site_...sub_addressesa |
#5
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Insufficient current over USB ports
As Krypsis says, a USB2 PCI card, is an easy way to modify the power
distribution. As long as the USB2 PCI card draws power from +5V for the ports, then you'd end up using a different rail on the power supply. Some USB2 cards, have an "Aux" power connector on the end of the card, which implies powering from +5V (just a guess). If the card costs $10, and you have a free PCI slot in the system, it's worth a try. Now we should get *powered* USB 3 adaptor. -- @~@ You have the right to remain silence. / v \ Simplicity is Beauty! May the Force and farces be with you! /( _ )\ (Fedora 15 i686) Linux 3.0.4 ^ ^ 22:56:01 up 5 days 2:09 0 users load average: 0.09 0.05 0.06 不借貸! 不詐騙! 不援交! 不打交! 不打劫! 不自殺! 請考慮綜援 (CSSA): http://www.swd.gov.hk/tc/index/site_...sub_addressesa |
#6
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Insufficient current over USB ports
On Oct 17, 8:58*pm, Man-wai Chang wrote:
I just discovered that the USB ports on my Asus M3N78-PRO motherboard are not supplying sufficient current. The result: power-demanding USB devices like a Canon USB 2.0 scanner and an iPod Touch 3 would appear then disappear then appear then ... in the device list. Isn't there a USB 2.0 standard for motherboard designers and manufacturers to follow? Or is it my Antec TruePower New 650W power supply? Why not get a powered USB hub, or is that a separate problem? -- * *@~@ * You have the right to remain silence. * / v \ *Simplicity is Beauty! May the Force and farces be with you! Ah, I see you are as much a fan of Chinglish as I am--very fashionable here in SE Asia. RL |
#7
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Insufficient current over USB ports
Man-wai Chang wrote: I just discovered that the USB ports on my Asus M3N78-PRO motherboard are not supplying sufficient current. The result: power-demanding USB devices like a Canon USB 2.0 scanner and an iPod Touch 3 would appear then disappear then appear then ... in the device list. Isn't there a USB 2.0 standard for motherboard designers and manufacturers to follow? I have a Verbatim USB disk that has a Y-shaped cable to get extra power from a second USB port. But it works on several PCs from just one USB port. It would not work on a set top box, which only supplies the standard 500 mA. It appears most PC USB ports pump out a bit extra, how much - who knows? |
#8
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Insufficient current over USB ports
On Oct 18, 8:41 am, "Orson Cart" wrote:
Man-wai Chang wrote: I just discovered that the USB ports on my Asus M3N78-PRO motherboard are not supplying sufficient current. The result: power-demanding USB devices like a Canon USB 2.0 scanner and an iPod Touch 3 would appear then disappear then appear then ... in the device list. Isn't there a USB 2.0 standard for motherboard designers and manufacturers to follow? I have a Verbatim USB disk that has a Y-shaped cable to get extra power from a second USB port. But it works on several PCs from just one USB port. It would not work on a set top box, which only supplies the standard 500 mA. It appears most PC USB ports pump out a bit extra, how much - who knows? The USB device reports its power requirement and the MB responds to a limit of 100ma. Supposedly, the Control Panel lists the connected item's power draw. On the MB USB jumper block, +5V or +5VSB is possible, although the second is STBY power for USB system wake-up events and not as well regulated as, preferably, selecting the first. Here's what's bloody well here at 3.0. USB standard of maintenance enforced by the USB Implementers Forum (USB-IF): For unconfigured devices, 150 mA of power is available, compared with only 100 mA of power in USB 2.0. 150 mA is considered one unit load. Configured devices are able to draw up to 6 unit loads, or 900 mA, a significant increase from the 500 mA available in USB 2.0. The added power allows for a broader range of devices to be bus-powered. [Tons of simultaneous broadcasting arbitrations in less-impaired restriction for disparate and earlier USB speed-locked, polled-event devices. Unicasting.] Link-level power management allows host or device to initiate transitional lower-level power status state. Low-power levels are configurable on the device level and the function level. [Based upon interrupt events, whereas prior USB events were polled.] Training, encoding, data scrambling [for line noise purposes], spread spectral energy emissions for dissipating peak levels at a smaller spectrum [EMC compliance], sideband low-frequency SuperSpeed USB3 (tm) communications, source clock variances and design result buffer elasticity (SKP implementation of dummy-data algorithms), LinkState SS.Disabled, untrained, to operate in USB2 compliance only and w/out SuperSpeed (protocol-driven streaming). http://www.totalphase.com/products/ |
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