Repairing a USB 2.0 hub

[Man-wai Chang]

What most likely kill the hub? Could it be repaired in general?

It's a Samsung PUH-7000NB.

[larry moe 'n curly]

Zapped by static electricity, despite the 12,000 volt rating of the chips?

A surge of current? I had an NEC-based USB 2.0 card lose 2 of its 4 ports because the tiny chip that was supposed to protect against current surges was damaged by one.

I'd try resoldering the connectors, including the one for the cable. Also there may be a blown fuse, which could look like a resistor or a surface mount part.

Sometimes Windows just won't recognize a USB device, so try booting the computer with an Ubuntu Linux CD.

[Sylvia Else]

Presumably it's powered by a plugpack, which may have died, and be replacable with something equivalent from your local electronics store.

Otherwise I'd expect it to be beyond salvage.

Sylvia.

[trader4]

The ones I've seen are all powered off the USB connection. And given the low cost of these not worth trying to fix, even if that were possible, which I'd say is not possible. Most likely it's the IC that's bad. Not much else there.

[Bob Villa]

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Considering your location...what would it cost you to replace?

[Man-wai Chang]

Don't wanna waste it *IF* it could be repaired easily... :)

[Sylvia Else]

If you take it apart, you'll likely find that it consists of a single IC and four USB sockets soldered to a board. There *might* be some capacitors.

There's not a lot there to repair.

You did try a different cable didn't you?

Sylvia.

[Tony Hwang]

Hii, Is you time that cheap? New one may cost ~5 bucks.

[Ian Field]

Do you have local recycling centers?

Bribe the site operator to let you have a few discarded hubs, you'll almost guaranteed find a few are GWO - that way you can save several other people wasting good hubs and have a couple spare.

[Jeff Liebermann]

I haven't done any autopsies on USB hubs. I've never seen one with just one blown port (unless it was mechanically damaged). What I have seen are problems caused by:

1. Plugging in the wrong power supply.
2. Applying power to a powered hub from a miswired adapter.
3. Bad electrolytic caps.
4. Miserable ROHS soldering usually combined with flux all over the PCB.
5. Probable package leakage on the chip.
6. Sometimes, the connectors are hand soldered, which leaves room for some sloppy soldering.
7. Counterfeit ID code causing operating system to install the wrong driver. Yes, you need a driver (USBhub.sys) to run a USB hub in Windoze.

From what I've seen, the last is the most common followed closesly by the bad soldering.

[Jeff Liebermann]

Thank you. It's good to see someone else interested in keeping electronics out of the landfill by repairing things, instead of just replacing them.

Much can be learned by simply disassembling the hub. With an inspection magnifying glass, look for bad soldering. Look for debris between the IC leads. Twist the board looking for intermittents. Check if 5VDC power is arriving at the chip. If the board looks dirty, clean it.

Good luck.

[A. Baum]

I have two 2.0 hubs I'll send you for free.