Hello everyone, recently I had to change my PSU (the old one, an Antec SmartPower 2.0 450W died on me and I received an Antec EarthWatts 500W as a replacement). After hooking everything up again, my USB ports don't work anymore. Everything else works (drives, cpu, fan, PS/2, ...), but the USBs are not getting any power (neither front nor back). The problem already manifests itself from the very beginning (USB keyboard not detected to enter BIOS), and when I'm in windows I have a 'USB Device not recognized' warning even though there is nothing plugged in. As I use USB sticks/drives quite a lot, I would like to know if there is a workaround to this problem (e.g. a USB-to-SATA convertor so I can plug my USB device in the SATA connector at the back of my motherboard (ASUS P5B). Or if anyone would have an idea how to revive my USB ports again, that would be even better... Thanks, Steven

It's possible, but extremely unlikely, especially with an Antec PS, that the USB circuits were fried because of the the old PS failing. Did it fail on it's own, or was there a definite or possible cause such as a power outage or spike or surge or a lightning strike near your location? Otherwise, installing the new PS, assumimg you installed any necessary extra connector the mboard may need from the PS other than the main one, should make the USB work fine. More likely is you're overlooking something. Make sure the USB controllers are enabled in the bios Setup. If you can't get into the bios, use a PS/2 connected keyboard. (A USB to PS/2 simple adapter connected to the USB on the keyboard cord won't work unless the keyboard is a "combo" designed to use both types of connections.) If you flashed the bios, you must load bios defaults or optimal bios faults after doing that in the bios Setup. If you flashed and didn't load bios defaults, the cmos and at least some of the settings in Setup in it are likely to not work correctly, whether they are default or custom settings. Or you could remove the AC power to the PS, move a jumper on the mboard to clear the Cmos, move it back after a few minutes, or you could remove the mboard battery and re-install it after a few minutes, but optimal defaults will probably produce a better result. If you removed then replaced the USB connections on a header on the mboard, or installed an additional connector for USB on a header on the mboard, if you also have one or more firewire headers on the mboard, the double row 10 position 9 pin Asus USB and firewire headers are identical - make sure you have connected the USB wiring to a USB header and not a firwire header, or visa versa. If you get that wrong, you won't notice anything wrong until you plug something into the USB (or firewire) port - but when you do, whatever you plug in will not work, and both the device and the circuits for the header can be damaged in a very short time. You may get odd error messages. ALL your USB ports may fail in that case. The USB wiring connector and USB mboard header wiring pattern was never standardized. The single wiring connector, or 4 or 5 in a row connectors, you connect to the USB header must be wired such that it/they jive(s) with what the pins are for on the header. If you plug in a USB wiring connector that did not come with the mboard, may sure the wiring of it is compatible with the pinout uses on the header. See the mboard manual, and the wiring description for the port adapter. Some case wiring for USB ports, and some wiring for USB ports on plate you install in a slot for USB ports, is not compatible with some mboard USB header wiring if it has 5 wires for a port. If that's your situation, when you connect all 5 wires to the mboard header from the USB port, you will get a message generated by the mboard bios about something such as overcurrent, even when nothing is plugged into any USB port. In that case - if there is a 4 wire in a row and a 5 wire in a row connector from a pair of ports, and 9 pins on the header, install the 4 wire connector on the 5 pin side, so you do not connect to the wire for a 5th pin (usually it's a second ground on the header, often the last black wire of two on the wiring connector ), and connect the 5 in a row to the 4 pin side such that the 5th wire is not connected. - if you have a single wiring connector for two ports, you will have to sever the 5th wire on one side, or remove it from the connector. - if you have two five in a row connectors for 2 ports, you will have sever the 5th wire in one of them or remove it from the connector (on the 5 pin side of the header) - it you have 5 individual connectors for each USB port, or three individual and one for a pair, do not connect the fifth wire to the mboard header (on the 5 pin side of the header). ..... If everything mentioned is fine - extremely unlikely - the new PS is putting out no +5v - in that case a floppy drive and optical drives will not work either - possible but we have very very rarely heard of it - the USB circuits on the mboard were fried because of the old PS failing, or by the same event caused it to fail. If that's your case, installing a PCI USB card in a slot should work, but I'm not sure whther you would be able to get into the bios with a USB keyboard in that case. "...a 'USB Device not recognized' warning even though there is nothing plugged in." The only other time I have heard of message similar to that when no USB wiring is plugged in, assuming you did not previously plug USB wiring into a fireware header or visa versa, is from someone who DID have fried USB circuits on his mboard. You could try disabling the USB controllers in the bios Setup in that case to get rid of the message, but it may not go away, and you may have to replace the mboard if that message bugs you, or if there's something else wrong with the mboard too, or if a PCI USB card in a slot does not allow you to get into the bios Setup with a USB keyboard and that bugs you.

Thanks for the elaborate reply. I don't know why my PS suddenly died. I came home one day and it was emitting a high-pitched (mechanical) tone while the computer was turned off (but of course the switch at the back of the PS was turned on). I read about an issue with bad capacitors on older SmartPower models and guessed that was the problem. Unfortunately I couldn't remove the mobo from its case (one of the screws is broken), which made maneuvering the PSU out of the case a very 'tight' process, in which I might have broken something. As for wiring, I haven't changed a single connection on the mobo except the 24pin connector and the extra 4pin which come directly from the power supply. Other than that I kept everything as is (also the 9pin USB connectors). I tinkered with the BIOS a bit (resetting to default settings; my USB keyboard works via an PS/2 adapter) but this didn't resolve anything. I'll try to clear the CMOS and see what that gives. If that doesn't work I'll go for the PCI-USB expansion card. Thanks!

I've heard of that - sometimes a power supply produces a noise when it has failed. The fuse inside rarely blows when a PS fails, according to what I've seen. If you're curious, if you open up the old PS and take a look, Pictures of blown capacitors, other components, power supplies, Athlon cpu's, etc.: http://www.halfdone.com/Personal/Jo... ATX power supplies are always powering the ATX mboard in some places, even when the computer is not running, as long as live AC is being supplied to the power supply and the power supply is switched on. Most motherboards have an led on them that lights up as long as live AC is being received by the PS to remind you of that. If you have no need to have the computer "wake up" to respond to something when you are not actively using it, it is a good idea to switch off what the power to the computer connects to when you're not using the computer, or switch off the switch on the PS if it's plugged in directly. It may not have prevented the PS from failing eventually if it was the PS itself that was defective, but it would probably have happened later rather than sooner, if you usually don't remove the AC power to the computer. On the other hand, a lightning strike near your location can still damage anything, even if the computer connects to a power bar or other device that protects it from power surges and spikes, and even if your have the AC switched off but it's still plugged in (e.g. a power bar still has at least the ground and sometimes one side of the power connected all the time). When people connect a power surge/spike protection device, they often don't realize they also need to protect everything that connects to AC one way or the other that connects to the computer, and the cable that connects them to the internet, too, and damage can be done because of that. .... If loading bios defaults and disabling the USB controllers in the Setup settings doesn't get rid of the message, clearing the Cmos will not either. Is the screw actually broken, or is it's head stripped such that you can't remove it normally? I've been able to remove such by gluing something to the head with epoxy or by soldering something to it. I'm assuming your model is actually P5B, and not one with something after that in the model (some other models will have just P5B printed on the mboard when they are actually a newer model or one with more installed options, such as P5B Deluxe). I downloaded a manual for your mboard and looked at it, and looked at pictures of it on the web. There is nothing on your mboard on the end nearest where the power supply would probably be in your computer case that has anything to do with USB - on some mboards the headers for the USB might be there, but that does not apply in your situation. As in the case with most mboards, the USB circuits are probably built into one of the two main chipset chips in your situation - those are a long way from the end of the mboard nearest the PS, and your USB headers are on the opposite end of the mboard. Did you have to remove the cpu and it's heatsink and/or the ram in order to remove the power supply? There are capacitors on the end of the board near the cpu socket that could have been damaged, but I can't imagine that affecting the USB at all. You have no firewire headers, unless you have an actual model higher than the original P5B. Therefore, I conclude your mboard USB circuits were probably damaged by the PS failing or at the same time the PS was damaged by some event you are not aware of that caused it to fail. If you need another mboard, you can still get your model, or slightly enhanced or newer ones in the same series, on the web. .... One last thing you could try is to flash the bios, but there's some definite risk in doing that - the relatively ancient type of cheap chip used for the bios isn't anywhere near as reliable as more recent chips used for USB flash drives and it can physically fail to flash even if you do everything right - make sure you use an update in the right bios update series, and read the directions for how to flash the bios - the best way to do that is by using the bootable floppy disk method, if that option is available. There's maybe a 1% chance, or less, that will work. After you remove the mboard battery and re-install it, or after you flash the bios, or sometimes when you clear the cmos by moving a jumper, the first time you boot you will get a "Cmos Checksum Error...." or similar message. You will either be prompted to enter the bios Setup or you will automatically go there. Enter the bios Setup, and load Bios Defaults - save settings, reboot. You MUST do this (or Clear the CMOS by moving a jumper on the mboard) in order to make sure the bios update is fully accepted by the mboard's bios - otherwise, the contents of the Cmos part of the bios and what you see in the bios Setup may not match the bios version, and your settings in the bios Setup may not work properly. If there is the choice to load Optimal defaults, use that - the bios should automatically use suitable settings for your situation. When you load bios defaults, usually the time and date setting is retained, and you don't get the "Cmos Checksum Error...." or similar message.

Well, there is definitely something strange going on. I searched in the BIOS to turn off USB but couldn't find the option; only something about legacy USB support, which I disabled. The "unknown USB device" still pops up, but not too much so that's not really a problem (although one of the entries under "USB controllers" in the device manager is "Unknown Device"). As I couldn't get the USB ports to work, I installed a Belkin USB PCI-card (F5U220). Even that doesn't work. I've got two more entries in the device manager now ("NEC PCI to USB Open Host Controller"), but they both have an exclamation mark next to them, and their device status says "This device cannot start (code 10)". And another "Standard enhanced PCI to USB Host Controller" which should work fine. But none of my USB devices get detected when I connect them. I went into safe mode and tried removing all entries under "USB controllers" (7 ICH8 controllers, 2 NEC PCI + Standard Enhanced PCI, 1 unknown device, 8 USB Root Hubs), but I could remove only the ICH8 and NEC ones (and afterwards they were immediately reinstalled by Windows). If I try to remove one of the others, the device manager locks up. I'm reluctant to flash the BIOS, but I guess that's about the only option left. Or maybe my PC is just haunted :) Thanks for your effort.

"I searched in the BIOS to turn off USB but couldn't find the option; only something about legacy USB support, which I disabled." Assuming your model is the original P2B, no numbers or letters after that, you are correct - I looked at the manual for that and there is no setting to turn on/off the USB controllers. Most bioses DO have such a setting. Disabling legacy support doesn't disable anything except the ability of a USB keyboard or mouse to be used to access or be used in the bios Setup while booting - Windows itself will still detect the USB ports and the devices connected to them. " I installed a Belkin USB PCI-card (F5U220). " Did you follow the proper installation directions? If the card is USB 2.0 rated, it also has USB 1.1 backward capability that is auto detected by Windows in any case. If you don't install the drivers for it properly, or if you don't have the proper drivers for your mboard main chipset loaded, you should see the regular USB (1.1) components for it are found fine, but you will have at least one entry in Device Manager probably under USB controllers for an unknown USB device or similar. ..... I have a strong suspicion your onboard USB circuits were physically damaged, either because of your power supply failing (much less likely with an Antec model), or because of some event external to the computer, such as power spike or surge, or a lightning strike somewhere near your location, that caused the power supply to fail AND damaged the mboard USB circuits, and possibly other mboard circuits, at the same time as well. If that's your case, if you cant' get the USB to work correctly by installing a card in a slot, you need to replace your mboard. You could try flashing your bios, but as I said previously there's maybe a 1% chance, if even that, that will cure your problem. Or you could try these things, but they probably won't help either: I'm assuming your 5v from the PS is okay Check the current voltages in your bios Setup. +5v should be within 10% of it's nominal value. If it's too high or too low, USB connected devices may not work properly, and/or if +5v or +3.3v or +12v are not within 10% of their nominal values, replace the power supply as soon as you can - it's failing. (or in this case, the circuits on the mboard related to the +5v or other voltages from which the mboard gets it's readings may be damaged) ..... A USB 2.0 controller card requires there be two IRQs be available for it in the slot is in - somtimes only one is available in a particular slot. You may need to plug the Belkin card into another PCI slot. See the following regarding not using the first PCI slot, and what is okay for the sharing of USB controller related IQs. ... Less common. An IRQ sharing problem. - If any of the USB controller related devices share an IRQ with another device other than another USB controller related device, that can cause weird problems, especially when a more sophisticated USB device such as a printer or scanner or modem or sound adapter or network adapter is also connected. Look in System Information on the left side - Hardware Resources - IRQs and see if another device is sharing an IRQ with a USB controller related device. It's OK for several USB controller related devices to share the same IRQ, and for USB controller card related devices in a slot to share an IRQ with onboard USB controller related devices, and for USB controller related devices to share an IRQ with other devices built into the mboard. If it's card other than that that's sharing an IRQ, try moving the offending card to another slot - don't use the last PCI slot on the end closest to the middle of the mboard for anything except a PCI video card - that slot is forced to share it's IRQ with the video and that usually causes problems. ...... (In your case, you could try this in any case) If a device was sharing an IRQ with USB controller related device, after you have cured that problem you must re-load the Windows USB stack. Open Device Manager. Un-install the USB root hub(s) and host controller(s) *in that order*. Unplug all USB devices. Win 2000 and XP (and Vista?)....... Shut down Windows. If your keyboard is USB...... hold the power button in until the computer shuts off. Plug in your USB devices, or at least your usb mouse and usb keyboard if applicable. Boot the computer. CHKDSK may want to run while booting - let it. Windows will automatically reload the USB stack. Try your USB devices. .. If your keyboard is PS/2.... Shut down the computer. If you have no mouse with all USB devices disconnected..... Hold down Ctrl and Alt, press Del, let go of the keys. Hold down Alt, press U, let go of the keys. Press U. Plug in your USB devices, or at least your usb mouse if applicable. Boot the computer. Windows will automatically reload the USB stack. Try your USB devices.