USB disconnects continously & problems at firmware startup

Red Water

May 6, 2022
I've got a server h/w supermicro X10SRA-F mobo that has been used for years as a desktop with the same configuration. But the last 3 months or so, I'm having problems, and I can't narrow it down.

  • on restart, it usually won't boot, unless I disconnect most of the USB peripherals, and fully power cycle the system
  • continuous USB disconnects, especially when doing videoconf, and the system webcam/audio freezes

This caused the whole system to lock up, until I put in an additional PCIe USB card for the audio & webcam, and moved them over to that. At least now I can save work, reboot when needed.


What I'm stuck on, is what is the underlying issue? I'm stumped at this point. Suggestions welcomed.
  • Flakey USB stuff on the mobo?
  • Insufficient power for various devices?
  • what exactly does the UEFI firmware do during this screen, that causes it to wedge on start up?
  • flakey devices? The webcam is cheap enough to replace, but the audio is not cheap, likewise the mobo


  • during videoconferencing, sometimes everything is fine, and sometimes it all gets wedged and audio + video are almost frozen
  • OS reports the USB hub has disconnected, and no amount of resetting fixes it
  • after that, the PC POSTs fine, but won't boot past this screen, neither from a USB key, nor from internal NVMe or disk drives
  • if I remove any USB device, it beeps contentedly, so its not completely wedged
  • if I remove the webcam + audio it boots OK


USB peripherals

  • these 2 are on the PCIe USB card to avoid lock-ups
  • Chord Mojo for audio (this is so good I love it) with a single USB-A cable that bifurcates to provide both power and audio signal
  • Logitech C920 webcam nothing fancy
  • these 3 are on the mobo own USB interface so I can still save work / reboot after lockups
  • yubikey
  • WASD keyboard
  • Razer Death Adder mouse
What I've tried without success
  • swapped out power supply for another one (SeaSonic Snow Silent 750W)
  • switched video card (GeForce GTW 1650)
  • dusted & cleaned the inside
  • re-set all the internal components and checked all power cables are properly seated
  • moved extra USB devices to separate *powered* PCIe card in the hope I spread the power out
  • run memtest86 for several days without any problems reported
swapping the peripherals around doesn't seem to help, it's the totality of them that seems to cause problems, but I don't see why that should be the case if they're on a separate USB / PCIe device, with its own separate power interface.

What have I missed?

ugen0.1: <Intel XHCI root HUB> at usbus0, cfg=0 md=HOST spd=SUPER (5.0Gbps) pwr=SAVE (0mA) ugen0.2: <vendor 0x04d9 USB Keyboard> at usbus0, cfg=0 md=HOST spd=LOW (1.5Mbps) pwr=ON (100mA) ugen0.3: <Razer Razer DeathAdder> at usbus0, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (100mA) ugen0.4: <vendor 0x0557 product 0x7000> at usbus0, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (100mA) ugen0.5: <vendor 0x0557 product 0x2419> at usbus0, cfg=0 md=HOST spd=LOW (1.5Mbps) pwr=ON (160mA) ugen1.1: <Intel EHCI root HUB> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA) ugen1.2: <vendor 0x8087 product 0x800a> at usbus1, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA) ugen2.1: <(0x1b21) XHCI root HUB> at usbus2, cfg=0 md=HOST spd=SUPER (5.0Gbps) pwr=SAVE (0mA) ugen2.2: <Yubico YubiKey OTP+FIDO+CCID> at usbus2, cfg=0 md=HOST spd=FULL (12Mbps) pwr=ON (30mA) ugen3.1: <(0x1b21) XHCI root HUB> at usbus3, cfg=0 md=HOST spd=SUPER (5.0Gbps) pwr=SAVE (0mA) ugen4.1: <(0x1106) XHCI root HUB> at usbus4, cfg=0 md=HOST spd=SUPER (5.0Gbps) pwr=SAVE (0mA) ugen4.2: <vendor 0x2109 USB2.0 Hub> at usbus4, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (100mA) ugen4.3: <VIA Labs, Inc. USB2.0 Hub> at usbus4, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA) ugen4.4: <USB Device USB 2.0 Hub> at usbus4, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (100mA) ugen4.5: <Chord Electronics Ltd Mojo> at usbus4, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=ON (0mA) ugen4.6: <VIA Labs, Inc. USB3.0 Hub> at usbus4, cfg=0 md=HOST spd=SUPER (5.0Gbps) pwr=SAVE (0mA) ugen5.1: <Intel EHCI root HUB> at usbus5, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA) ugen5.2: <vendor 0x8087 product 0x8002> at usbus5, cfg=0 md=HOST spd=HIGH (480Mbps) pwr=SAVE (0mA)
Failing usb ports or controllers? I have that issue going on now with my asus p6x58d-e, mostly when using a hub and drawing too much power.

Check the pins in the USB ports, make sure none are mangled or flattened. They should have an arching nature.

Did moving stuff to a separate PCIe card help or not? I may have missed that.

Try wiggling all of the cables while connected, looking for internal damage.
thanks - cables duly wiggled, and usb pins are aligned. The voltage sounds like the next thing to check, need to do some reading on that first.

Today I found that the PCIe USB card was sharing the same connection to the power supply as all other peripherals including 4 disks, so I moved it off to its own direct connection to the power supply, and replaced another power cable just in case, the connection seemed infirm.

After this, the system refuses to boot if any devices are connected to the PCIe card, and hangs at the "A2" phase. Which is IDE Detect according to supermicro.

I can boot fine with no peripherals hanging off the bus, so I might be able to get past this if boot from USB is disabled in UEFI firmware, thats worth a try. After boot, system is totally fine with them all plugged in. Go figure.

Hopefully the power changes today will stabilise things, won't know until I've done a few conferences this week.
Red Water - and what, did you manage to solve the problem? If not, it would be best to contact your Supermicro distributor. Surely they have already had a similar case and will be able to help you.