USB hub does not always initialize on boot

**d_sellers1** · 05-28-2006, 03:31 AM

I've got a GWC 7-port USB hub that is running just fine unpowered. However, sometimes when I reboot or shutdown, the USB hub will not initialize. I am not sure if this is a mobo, BIOS, or hub issue. If I just unplug the USB cable running from the hub to the mobo and plug it back in, all the USB devices initalize just fine.

But this is not something that I am going to want to do when I get the system moved in to the car. For my next point I want everyone to remember that most USB ports still supply power even when the computer is off. Running on the bench with a normal PSU I assume my USB ports are staying active. I'm hoping that when I start using the OPUS in the car I will not have this problem but I still want to do my research ahead of time. The OPUS should cut all the power to the mobo when I put the system into hibernate.

If it still happens with the OPUS then here is another option:
Splice in to the +5VDC wire in the USB cable and add in a relay. I the +5VDC from the OPUS to use as the trigger. In theory, when the OPUS is off, the relay path will be broken (unplugged). When the OPUS is on, the relay path will be closed thus act as if it is plugged in...

Another option would be to run the hub with the power adapter. Don't think this is going to solve the problem.

Since I've been typing this I remember reading a post about OPUS and USB port issues. Time to go searching but I am still going to post this topic and see where it leads to.

Derek

**v8 scimitar** · 05-28-2006, 06:24 AM

the opus doesnt cut the power to the 5v line unless your batery level drops.
Go into the device manager when the items arent working and see if they show up and if they do see if they are active or dissabled. You might need to use something like devcon to dissable and enable them although this is usually only needed for hibernation. Better option that will save your batery as well is to use Randos circuit to cut the 5v to the mobo if you intend to shut down all the time. I havent used this myself but dont think this would cure the hibernation issues so I guess the ultimate is to use the circuit and Devcon along with hibernate triger and some scripts. Remember the scripts and Devcon only disconect the software and not the voltage so it isnt a replacement for the relay and diods.

**DeltaFX** · 05-28-2006, 01:58 PM

Run your hub with the external power adaptater.

Then cut the + line in your "Hub-To-Mobo" cable.

Use a relay to cut the external power adapter, and control it with a molex 12v. PC is Off => 12v is off => relay is open => No power at all to the hub.

**d_sellers1** · 05-28-2006, 07:35 PM

Originally Posted by DeltaFX

Run your hub with the external power adaptater.

Then cut the + line in your "Hub-To-Mobo" cable.

Use a relay to cut the external power adapter, and control it with a molex 12v. PC is Off => 12v is off => relay is open => No power at all to the hub.

Sounds like you and I are thinking along the same lines however at this point I an not quite sure that powering the hub is going to make a difference. The hub powers the devices that I currently have attached to it with no problems. The only problem is that sometimes the BIOS does not activate the hub. The relay trick is going to be one of the first things that I'm going to look in to.

Before I do that though, I found the article regarding the OPUS and USB ports. It involves putting a DPDT relay on the PSON and 5VSB wires on the ATX cable. When the power is off the the circuit is broken thus turning off the 5VDC standby power to the mobo. It also prevents the system from draining the battery. This is going to be the first thing that I set up...

Thanks for the input. Love to hear more thoughts and ideas.

Derek

EDIT: 3 out of the 4 times that I have rebooted in the past few minutes, the hub initialized with no problems...

**DeltaFX** · 05-29-2006, 04:34 AM

Dsellers, if, asI said, you cut the +5v wire in the usb cable, the hub is not getting any power from the mobo, so external power is needed.

**d_sellers1** · 05-29-2006, 04:41 AM

Originally Posted by DeltaFX

Dsellers, if, asI said, you cut the +5v wire in the usb cable, the hub is not getting any power from the mobo, so external power is needed.

Yeah but the bigger problem is going to be the fact that the motherboard is going to be drawing the +5v from the OPUS and can thus drain my battery. If I cut the +5v line between the OPUS and the mobo solves both issues (battery drain and hub problem) at one time with the least amount of work.

Besides, my first post suggested putting a relay in the +5v wire in the USB cable to open/close the circuit. This would create less wires running around.

Derek