Repairing a USB 2.0 hub

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

It's a Samsung PUH-7000NB.

-- @~@ Might, Courage, Vision, SINCERITY. / v \ Simplicity is Beauty! May the Force and Farce be with you! /( _ )\ (x86_64 Ubuntu 9.10) Linux 2.6.38.2 ^ ^ 17:31:01 up 11:42 0 users load average: 1.07 1.07 1.05 ???! ???! ???! ???! ???! ???! ????? (CSSA):

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Reply to
Man-wai Chang
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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.

Reply to
larry moe 'n curly

Hubs are so cheap -- most are made in China -- you might as well replace it.

This might also be a good time to put a USB 3.0 card in the computer.

Reply to
William Sommerwerck

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.

Reply to
Sylvia Else

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.

Reply to
trader4

you!

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

Reply to
Bob Villa

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

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Reply to
Man-wai Chang

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.

Reply to
Sylvia Else

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

Reply to
Tony Hwang

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.

Reply to
Ian Field

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     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
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.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

Yes, if it has a PCI-E connector on the motherboard.

So, at what point do I recycle and replace, instead of repair? Well, I allegedly charge $75/hr. Fixing even the most trivial device will take about 30 minutes, most of which is cleaning up the mess on the bench, and doing the inevitable paperwork. That makes the break even point about $40. Anything worth less than $40 cannot be profitably fixed. So, I'm suppose to toss mice, keyboards, numerous small PC cards, disk drives less than 120GB, calculators, floppy drives, speakers, wall warts, and USB hubs. No wonder I'm losing money and have too much junk.

Extra credit: Calculate the cost of handling a zero cost repair. That's a repair job that requires zero time and materials to fix, but still requires, handling, paperwork, overhead, and possibly shipping. The last time I did that, based on 200 working daze per year and an 8 hr day, I needed to charge about $100 for a zero cost fix.

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

We are caught in a dilemma... If stuff is made to a high quality standard, then it won't break down very often, and won't need the repair. But -- to some degree -- we need stuff to break down to encourage people to buy new technology, which appears at an ever-faster rate.

Reply to
William Sommerwerck

The company motto is: "If this stuff worked, you wouldn't need me". It's on all my stationary and business cards. Nobody has disagreed in the last 30 years.

Designed obsolescence is one of the unpleasant side effects of CAD (computah aided design). When it is possible to model the lifetime of a product on a computah, one can easily design a product for a specific life. For example, electrolytic capacitors can be selected for a target lifetime based on temperature, ripple current, and voltage rating. The life of power semiconductors can be estimated by dissipation, temperatures, and the number of power (thermal) cycles. If I offer a 1 year warranty, I would probably design for a 2-3 year life. For a 5 year warranty, I would use better parts and run at lower temperatures. Sometimes, I wonder if the bad-caps problem is the result of manufacturers realizing that having products blow up after some predictable time isn't a bad idea, and intentionally using junk caps. (Everything is a conspiracy).

--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

I have yet to see any business from my usenet rants, so I'm not worried. In theory, I should charge for literally everything. It would not show up as a line item on the invoice, but would be part of the hourly labor charge. The only labor I charge for separately are travel time, expedite fees, waiting for the customer to get out of a meeting, nobody home charge, and entertainment value[1].

The entertainment value discount requires a bit of explanation. I will sometimes charge $1 million, on the invoice, for some effrontery such as interrupting dinner, not following instructions, failing to make a backup, or wasting my time. However, none of my customer are expected to pay $1 million, so I balance out these charges with an entertainment value discount of $1 million. I don't make any money on this, but it does get their attention. Unfortunately, I don't do this any more because my bookkeeper got irritated and thought that an auditor might be equally irritated.

My guess(tm) is that I burn about 30 minutes per working day doing nothing more than keeping my messy office and workbench from fatally degenerating into an unusable mess. Someone has to pay for this waste of time, and it's NOT going to be me.

[1] I've had only 1 bounced check in 30 years, so I don't bother with the usual bounced check charge.
--
Jeff Liebermann     jeffl@cruzio.com
150 Felker St #D    http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

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

Reply to
A. Baum

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