Underpowered USB Ports

[ikissfutebol]

After installing a second storage drive, I have decided to totally wipe everything from my current desktop (built 12/2008) after Windows 10 is launched. My wife has an external hard drive that works with every single full USB port in the house, except for the 8 ports on my desktop (6 back, 2 front) - Winbook tablet, Surface RT, her Windows 7 Dell laptop, and our router. It sounds like the drive isn't getting enough power when plugged into my desktop. I have an old laptop drive plugged into a basic enclosure that has the two USB cords coming out of the one side. Same deal - works on everything except my desktop. I have reset the capacitors (holding power for 10 seconds while disconnected from power), BIOS is current version - hasn't been flashed in a while, but it's obviously an old motherboard.

Every other device I plug into my desktop functions just fine - USB flash drives, card readers, dongles, Logitech G13 gaming pad, etc. A few times, and with no rhyme or reason, if I plug a USB device into my desktop the system insta-reboots itself on its own. It hasn't happened for a couple of months so maybe there was a funny Windows Update or something?

I have a terribly crappy self-powered USB hub. Once today I got both drives to work. I'm not sure if it was a fluke - upon disconnecting the enclosure, the external drive was disconnected, too. Now, I cannot get them to get recognized. I can get them to at least sort of power on if I have them both connected to the hub at once. To me, this sounds like my motherboard just isn't sending enough power and the self-powered hub is only going into self-powered and not bus-powered mode if it recognizes a need. Looking in device manager, Windows says my desktop is sending 500 mA per port (for the 8 built in, not the hub). If I turn off the enclosure, Windows makes the sound for a USB device getting disconnected, however, I can find zero traces any where that indicates Windows recognizes it.

Three questions-
1) is this a sign my motherboard is dying after almost 7 years?
2) is there anything I can do to pump out more power or even verify each port is receiving 500 mA?
3) would a PCI USB card provide more reliable

Motherboard: ASUS M3A78 with the most up to date drivers
CPU: Athlon Phenom x4 9950 (not overclocked)
PSU: 600W
GPU: Radeon 7750
OS: Windows 8.1 Pro

 

[norsestar]

I'd suggest a PCIe x1 USB3 card if you've got a slot available, or a self-powered USB3 hub. USB3 provides up to 900mA vs. USB2's 500mA and is backwards-compatible.

To answer your questions:
1. Unless it worked before and doesn't now, no, it's probably not the motherboard dying.
2. You could get more power by wiring the USB +5V pin directly to the power supply, bypassing any switching and current-limiting circuits (not recommended). You could verify 500mA per port by applying a 10 ohm load to each (which might require forcing or tricking switching circuits on). Also not recommended.
3. A USB3 card would probably work due to the higher current limits. I had bad luck with several USB2/PCI cards trying to power a 2.5" drive: none worked reliably.