USB Hubs in Dell monitors - powered?

[HCHTech]

I'm trying to diagnose a problem at one of my clients that has the micro form factor Optiplexes. They have Dell P-series 24" monitors, that have the 2 USB ports on the side of them. The monitors USB connection is "Type B". Does anyone know if the monitors supply their own power to the USB ports?

I've got a situation where things will work when plugged into the monitor, but not when plugged directly into the computer. This is an auto shop - they have a barcode scanner and a laser printer (both currently plugged into the monitor - which allows them to work). Otherwise, there is just keyboard & mouse plugged into the computer (which also work). Plugging in a flash drive to any of the unoccupied USB ports on the computer doesn't work - no recognition tone and no drive showing up in explorer or disk manager - as if they are not connected.

The original symptom was that the printer stopped working - and I haven't been onsite yet, but just talked them through some things to try. These are pretty new units, only a couple of months old. I'm wondering if those micro PCs have don't have enough juice, their power bricks are only 65W. Both the laser printer and scanner wand are old, so maybe something is at fault there as well. For now, plugging them into the monitor USB ports made them work, but if there is a problem with the computer itself, I don't want to wait before starting down that path. Something isn't right if the computer can't even detect a flash drive. We've got a couple of dozen of these microPCs out in the field - I hope this doesn't turn out to be one of their weaknesses...

 

[nlinecomputers]

Yes they are powered, there is a setting in the monitor menus to enable power when the monitor is off.

 

[Sky-Knight]

Some are powered... not all are. (I'd dare say most, but I've run into a few that weren't)

Given what you're reporting I'd say it's fair to assume the Dell display you're working with is powered. And if that display's powered hub is sorting out access, either the devices they're working with are incompatible with the desktop's USB bus, or they're as you assume... not putting out sufficient power to energize the device.

I've never had a printer not work due to low USB power... because they have their own power. Nor have I ever had issues with USB keyboards and mice. BUT... I have had plenty of issues with USB POS equipment, bar code scanners, light poles, etc. It got to a point where I started using powered USB hubs for all my POS installs just to ensure things worked. It also gives me a nice single place to "unplug" everything via an IP Power switch.

 

[nlinecomputers]

I’ve NEVER seen a Dell P series monitor that didn’t provide power. YMMV on other brands or other Dell monitors but the P series is powered, it one of the selling points for the monitor.

 

[Sky-Knight]

That is a fair point, my comments weren't limited to Dell P-Series, as I missed that detail when I scanned the post. Instead I was thinking Dell monitors with USB.

 

[HCHTech]

Ok - thanks guys. Unfortunately, this is the front desk/checkout computer, so there isn't much downtime to check things out. When it's not in use, they are closed and no one is there. When they are there, it is in use and can't be taken down - not exactly something that can be troubleshooted (troubleshot?) remotely, either. Ugh - I guess I'll have to ask them to open up on a Saturday for me to figure this out. Ugh.

 

[nlinecomputers]

Ok - thanks guys. Unfortunately, this is the front desk/checkout computer, so there isn't much downtime to check things out. When it's not in use, they are closed and no one is there. When they are there, it is in use and can't be taken down - not exactly something that can be troubleshooted (troubleshot?) remotely, either. Ugh - I guess I'll have to ask them to open up on a Saturday for me to figure this out. Ugh.

I can easily see one of those mini's not being able to power a scanner. What is wrong with it plugged into the monitor? You'd have to drop in a powered hub which is the same thing.

 

[NJW]

Plugging in a flash drive to any of the unoccupied USB ports on the computer doesn't work - no recognition tone and no drive showing up in explorer or disk manager - as if they are not connected.

The original symptom was that the printer stopped working - and I haven't been onsite yet, but just talked them through some things to try. These are pretty new units, only a couple of months old.

I'll wager that you haven't heard the full story!

Are we opening a book? Physical damage to the USB port is my pick, shorting the +5 V supply. Possibly the USB power controller has hung following an overload and needs a full power-off (supply unplugged) to reset, but that's a longer shot.

There will be at least two internal USB hubs, so one bank of ports working and another not, is not out of the question.

Or a weird Dell USB2.0/USB3 conflict. Recent driver update?

 

[HCHTech]

I can easily see one of those mini's not being able to power a scanner. What is wrong with it plugged into the monitor? You'd have to drop in a powered hub which is the same thing.

Yeah, nothing wrong with using the monitor hub - it's the dead ports on a new computer that is the concern - just have to deal with it, that's all. I hate stuff like this on a new install, not really a big deal, just unfortunate. Hopefully if it is hardware, it will be covered by Dell. We'll see. At least we made them get a UPS, so hopefully won't get blamed if it was a power thing. Plus - they're MY mechanic and very good so I don't want to sully that relationship either!