USB Hub not working

I have one of these USB hubs with several USB connectors, which plugs into a single USB port on a computer. It dont work. If I plug in a flash drive directly to the computer, I can access that drive. But if I plug it into the hub, the drive never shows up. I tried this on 3 computers.

I opened that hub, and there is a circuit board, with each output port connected to a trace on the board which goes to a black dot on the board. I dont know what that "dot" is, but I assume it's a chip of some sort, and it looks like the dot itself was some sort of epoxy placed in the board.

This was a gift, and it's going to get returned to the store, but I am just wondering what kind of circuit this is?

Until looking at the innards, I thought that these hubs were just a direct connection to the input (from computer) USB. But I see there is more to it....

Reply to
oldschool
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Which version of which operating system? How old is the computer? What happens when you try it on a different computer? What does device manager say? What happens when you boot a linux live CD? Make/model of the hub? Somebody may have one and actually have a direct answer. There were hubs that required you to install a driver, but that was a LONG time ago. But "oldschool tubes" suggests you might have really old stuff ;-)

Reply to
mike

snipped-for-privacy@tubes.com wrote on 12/30/2017 12:02 AM:

USB is a point to point interface unlike some versions of Ethernet (using coax) or an RS-485 multipoint interface. To connect more than one device to a USB port requires a hub. The hub has a chip which receives packets sent from the computer as well as packets received from any of the down stream ports, buffers them and retransmits them on the appropriate other port. That multiport interface chip is what is under the blob of epoxy on your board. They use a chip directly with no package because it saves a few pennies.

When you plug the hub into your computer it should show up as a hub. Under windows you can go into the device manager and find it there. If the driver did not install correctly it will show with a yellow error symbol next to it and be listed as an unidentified device. If it doesn't show in the device manager list at all while the flash drive works in the PC port, the hub is defective. If it shows up but with the driver error, you may need to search the Internet to find a driver.

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Reply to
rickman

There are hubs that come with a power supply so they can deliver more power to the connected devices than can be supplied by a single port at the computer, and there are hubs without powersupply.

It may be that yours has the powersupply misplaced and won't work without it. Look for an extra connector on the case that is not a USB input or output.

Reply to
Rob

The blob conceals an silicon chip mounted on the board this type of construction is called "Chip On Board" or "COB" the chip does the signal routing, translation, and forwarding and needed to support USB hubbing

Yeah, somehow they call it USB but electrically it's not what I would consider to be a bus.

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Reply to
Jasen Betts

Reply to
pfjw

Return it? Those are give-aways. Toss it.

Reply to
Terry Schwartz

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