BUFFALO WLI-U2-KG54-AI USB adaptor stopped being 'recognized'

I don't know whether I misread your previous post or not but I was referring to the USB ports in my laptop.

On Wed, 07 Mar 2007 10:28:07 -0800, Jeff Liebermann wrote in :

I just checked a small generic 4-port powered/unpowered hub, and it reports 0 mA both in its own device manager entry and in the entry for the root hub.

Thanks Jeff,

Doesn't really help me with checking the output capabilities of my laptop's ports directly, but it has enabled me to check the adaptor via the pc and confirm that the 'power' tab rates this as 400ma and my 1Gig flash drive at

100ma - rather indicates it's not a good idea to have both pluged into the laptop at the same time, but looks like I'll have to plug 4 flash drives in at once to see if the laptop can manage the power of the buffalo. I'm one short at the mo...

Cheers, S

On Wed, 07 Mar 2007 19:08:59 GMT, "Steve H" wrote in :

Why? That's not greater than the power capability of the port.

Do I have to spell it out?

I am wondering (amongst other things) if there is a bad connection somewhere on the laptop's USB port hardware that is stopping it from being able to deliver enough power to 'start' the wireless adaptor, but is still capable of delivering sufficient to be able to run flash drives.

(I have had a look at opening up the laptop to get at the port assembly and check its contacts, but it seems to be very difficult to get at, requiring just about every other component to be removed first.)

S

Checking some more, I find that with my unpowered pocket hub plugged in, it registers as '500ma' on the power tab, and plugging in three flash drives to this makes no difference. Thus the power tab is not giving any information about actual power consumption at all - it is just trotting out text from whichever device is closest to the port.

S

On Wed, 07 Mar 2007 21:38:24 GMT, "Steve H" wrote in :

What it's actually trotting out is whatever all the connected devices are telling it. No actual power monitoring is done.

On Wed, 07 Mar 2007 21:06:45 GMT, "spamlet" wrote in :

I guess so. :)

Very unlikely. I think you're chasing the wrong problem.

Better to try a different adapter. Seriously.

Yes: It looks like I've run out of options on this. I would have liked to be able to find out what was really going on though.

Cheers,

S

Kev hath wroth:

I was refering to the original posting which dealt with an unpowered Sitecom Pocket HUB CN-032. There's no way I can tell what machine you're talking about from your one line posting: "It's different on mine. I have 4 ports and it specifies that the Hub is self powered and total power available is 500ma per port." The issue is directly related to the problematic Buffalo WLI-U2-KG54 USB device as it might be drawing too much current from an unpowered hub if other devices are also plugged into the hub at the same time.

What I was trying to get across is that:

1. You can get an idea of how much current a device can draw from the USB device entry in the Windoze Device Manager or a variety of utilities that will do the same thing. (i.e. Unknown Devices).
2. Not every device reports its current drain in the Device Manager.
3. Some devices lie. For example, wireless USB devices draw more current in transmit than receive. Yet, I've seen only the receive current reported. Adherence to standards is also somewhat problematic as indicated in the Wikipedia article you posted.
4. The current is NOT a measurement of actual current drain, but merely a number reported by the device.
5. The maximum load is 500ma per port for a powered USB hub, and

500ma for the entire hub, for an unpowered USB hub.

"spamlet" hath wroth:

I don't think that's happening. I've seen broken connectors and blown fuses on USB devices. The usual result is an all or nothing affair. It either works, or it doesn't. There's too much data negotiation and error checking going on for anything to partially fail in the manner you're experiencing.

Dell Inspiron 2600 as I recall. It's not listed here:

You should be able to find disassembly instructions in the docs on the Dell web pile. Bug me if you can't find them. I don't think you'll be able to see the connections to the main PCB as many such USB connectors are surface soldered. The better ones use plated through holes in the PCB. With these, the leads are under the connector and difficult to see.

There are also dedicated USB test tools and software avaialable. I haven't used any. Search Google for "USB tester".

Thanks Jeff,

I do have the laptop's service manual from Dell, and it doesn't say anything about the USB ports as such, but it is clear from the way the strip down is sequenced that these would be one of the last things to be uncovered - and I think I'd be quite likely to break something before I got that far!

Meanwhile, after an afternoon of use on the pc, I plugged the adaptor into the laptop again and was surprised to see both the Buffalo Wireless LAN Adaptor AND the associated Buffalo Miniport Package Scheduler, appear in device manager. The former soon dropped out to its yellow triangle state, with the 'device cannot start code 10' message. On a whim, I put this into google and checked some of the threads to come up with this one:

where quite a number of contributors do seem to be of the opinion that there was a problem with older boards not being able to cope with the power requirements of the later USB devices. This is getting me increasingly confident that this really must be the cause, and I suspect that your original idea of obtaining a USB2 card may be the way forward. One thing to clear up: will the laptop be able to deliver power to the USB2 card any better than it could to the old USB2 ports; and if not would a wireless adaptor CARD be likely to fare any better than the USB adaptor has?

Kind regards,

S

No guts, no gain. By coincidence, I just tore apart an older Dell Inspiron 8400 laptop down to the motherboard removal to replace the power connector. Total time was 1.5 hour from start to finish (ignoring a few interruptions). It's no big deal once you've done a few of them. The most difficult problem is trying to remember the location of the screws and fasteners. For that, I use my digital camera. I take a photo of the top and bottom, print it on my laserjunk printer, and push the screws through the paper in their original location.

where quite a number of contributors do seem to be of the opinion that there

I've seen that with trying to power 2.5" laptop drives from the USB port. At this very moment, I have a Toshiblah 80GB laptop drive plugged into a USB2 to IDE adapter cable (very handy when it works). Windoze Device Manager on my desktop reports 0ma of current drain from the drive. Same garbage on an IBM A31 laptop. However, when I try it on my ancient Micron laptop, I get the "cannot start error code 10" message, which just means that the USB ports in the Micron are a problem. My guess(tm) is that the USB standard demands that during initialization, the USB device should suck 100ma or less. Few devices do this, especially this hard disk trying to start. So, the older USB ports and chips are picky and enforce the standard while the newer USB ports and chips are more tolerance of abuse to the USB specification and tolerate the high startup current. I have a butchered USB cable (somewhere) setup to measure the device current, but no Buffalo USB adapter to test.

Yet another coincidence. The IBM A31 laptop has USB 1.1 ports only. So, I purchased a Sabrent SBT-P2D PCMCIA to USB2 cardbus thing. The customer uses it mostly for backup to an external USB hard disk, but normally has a large number of USB devices (9?) plugged into various USB hubs connected to the card. Without USB 2.0, his laptop ran at the speed of sludge.

I'm not sure if the problem is whether the port can deliver the power, or whether the port is shutting down to soon from overload. I think you would be better off power wise with a PCMCIA USB2 card. 2nd best would be a *POWERED* USB hub. The main reason I suggested the card is to be able to use your Buffalo wireless device at 54Mbits/sec, instead of being stuck at 11Mbits/sec max with USB 1.1.

More useful thoughts Jeff,

If twere my own laptop and I was convinced that I would be likely to find and solve the problem by the strip down I would go ahead (And certainly digital cameras do make it wonderfully easy to document a strip down and make one's own workshp manual as it were - years ago I rebuilt an automatic gearbox without a manual and had to draw every part as I went along, and make my own special tools!), but as this particular laptop is on long term loan, and the omens are that the problem is inheirent in the system, I think the other alternatives you suggest will be safer.

What would you think of the combination of wireless PCMCIA CARD, and separate powered hub? Obviously a heavier/bulkier combination to carry around than the USB2 card and USB wireless adaptor, but would the extra power be an advantage over trying to drive devices via the laptop's supply?

Also, I had a brief Googling on USB PCMCIA cards, and there seems to be an enormous range, both in numbers of ports and in prices. Is more expensive better? Is more ports better? (I have my mini extension hub after all.)

Thanks as always,

S

>where quite a number of contributors do seem to be of the opinion that

Oops! Sorry Jeff: you already told me: a powered hub would still leave me communicating at USB1.1 with the laptop itself. I'd still appreciate your advice on choosing the right card though.

Cheers, S

>>where quite a number of contributors do seem to be of the opinion that

More gleanings from the customer comments under a number of PCMCIA/USB2 adaptor cards:

A number of these cards come with their own power supply or a socket for one; There are many comments as to devices being unable to start without an additional power supply; One commenter points out that the 'PCMCIA bus' is limited to 100ma and cannot deliver the 500 associated with a normal USB port.

Looks rather likely that my Buffalo adaptor is not going to work in a USB2 adaptor card without an external supply, so it will not be a portable solution after all.

Now, does this 100ma limit mean that this laptop might not even power a PCMCIA wireless card...

>>>where quite a number of contributors do seem to be of the opinion that

You missed a decimal point.

It's 1000ma per card. However, the recomended continuous power drain is 500ma total per card. See:

What power is available to a PC Card slot?

The PC Card connector pins are rated to a maximum of 0.5 A per pin, which means the maximum possible current available over the two Vcc pins is 1000 mA. However, the Host System Specification chapter of the PC Card Standard set a recommended minimum current per slot, which is the most any PC Card card designer should expect to be provided by a host slot. PC Cards requiring more current than the host minimum recommended support values may not be powered properly in all systems.

Type 3.3 V Value 5.0 V Value Peak 1000 mA 660 mA Average 750 mA 500 mA Static 500 mA 330 mA

Most modern laptops are 3.3VDC.

That's means that a two port PCMCIA USB card can source 500ma per port, but the recommended maximum is 500ma total divided between the two ports.

On Thu, 08 Mar 2007 19:56:06 GMT, "Steve H" wrote in :

Better USB 2 PC Cards use external power supplies.

Thus it is begining to look as if I won't be able to reliably use the laptop on USB2 devices or devices that need more power than the minimum, unless I buy another device that needs mains power. thereby nullifying the point of the laptop in the first place...

Mind u, As it appears that as Jeff has noted, a 0 was left off the power capabilities of PCMCIA bus info I had found, then this would appear to make it more likely than the laptop may power a wireless PCMCIA card directly.

Still not sure about buying either this or the USB adaptors though, as in all the comments from customers - on sites that provide them - there appear to be somewhat similar stories to my own, with them only working for some devices. I have not, as yet found any customer reviews of the wireless cards (Buffalo at least), to be able to tell whether there are similar 'unrecognized' problems with these as well.

Anyhow, Thanks both of you for all your research on my behalf.