Leo Bing Whiteway (leobingw@gmail.com) writes: > I was given a 10 gig USB hard drive. It has a jack marked +/- and a cable with a > USB plug on the end made to plug into a USB socket on the computer. It also > has a USB cable. > The hard drive has: > HI-SPEED > CERTIFIED USB > USB 2.0 TM > I have no more info on it and can't find it with searching Google. > I am having no luck making it work or show up in lsusb. > Have any of you any ideas where I might look for info on how to hook it up and > try to use it? > That +/- jack sounds like it's for an AC adaptor to plug into. I have very little experience with USB, and none with USB drives, but I would think a hard drive might be pushing the limit of power available over the USB bus. Hence perhaps it needs an AC adaptor to power it up before it will work, rather than getting power from the USB bus? SInce it was given to you, that's the sort of situation where an AC adaptor gets lost along the way. You'll have to find out, or figure out, the needed voltage and current. Polarity is important too, but that +/- sounds like it might define that point at least. Look for labels that might provide the information. Look closer just in case the jack is actually marked (I've found some of that sort of marking can be hard to see if the color of the plastic is wrong). I usually find such details with web or newsgroup searches. It's always interesting how many time someone has asked about a given unit's power requirements in the past, or someone selling a unit somehow includes the power requirements when advertising it. Failing that, open up the box and see if there's a clearer indication of the manufacturer. At the very least, one might start to make a guess, use an ohmmeter to see which of the jack's pins goes to ground, then follow the other line to see what it's connected to. An electrolytic capacitor is likely connected at some point to where the power comes in, and the voltage rating on the side at least sets a point where the voltage will be too high. Michael

"Leo Bing Whiteway" <leobingw@gmail.com> wrote in message news:hLUQi.32996$%B2.28876@edtnps82... >I was given a 10 gig USB hard drive. It has a jack marked +/- and a cable >with a USB plug on the end made to plug into a USB socket on the computer. >It also has a USB cable. > The hard drive has: > HI-SPEED > CERTIFIED USB > USB 2.0 TM > I have no more info on it and can't find it with searching Google. > I am having no luck making it work or show up in lsusb. > Have any of you any ideas where I might look for info on how to hook it up > and try to use it? If I'm guessing right, the drive isn't getting enough power from the USB port and either doesn't spin, or spins rather erratically. Try connecting the +/- plug to an AC/DC converter running at 5 Volts. Make sure the polarity's right. Geo

Hactar (ebenZEROONE@verizon.net) writes: > In article <ff1d2c$1j$1@theodyn.ncf.ca>, > Michael Black <et472@FreeNet.Carleton.CA> wrote: >> Leo Bing Whiteway (leobingw@gmail.com) writes: >> > I was given a 10 gig USB hard drive. It has a jack marked +/- and a >> cable with a >> > USB plug on the end made to plug into a USB socket on the computer. It also >> > has a USB cable. >> > The hard drive has: >> > HI-SPEED >> > CERTIFIED USB >> > USB 2.0 TM >> > I have no more info on it and can't find it with searching Google. >> > I am having no luck making it work or show up in lsusb. >> > Have any of you any ideas where I might look for info on how to hook >> it up and >> > try to use it? >> > >> That +/- jack sounds like it's for an AC adaptor to plug into. I have >> very little experience with USB, and none with USB drives, but I would >> think a hard drive might be pushing the limit of power available over >> the USB bus. Hence perhaps it needs an AC adaptor to power it up >> before it will work, rather than getting power from the USB bus? > > I think 3.5" drives take 12V to run the spinny-bits motor, at more > current than it can extract from the 5V@500mA that USB provides. > You're right, drives do generally need 12v in addition to 5v. But, they will never get that needed 12v out of the USB bus, since the USB bus doesn't provide anything but 5v. I would be quite hesitant to start with 12v, for the simple reason that if the drive is expecting less voltage, you risk doing damage. We don't know what's inside the unit other than, obviously, the hard drive and a USB to whatever (presumably IDE) converter. It may run off 12v and then drop it internally for where it needs 5v, or it may start with 5v and shift it up to 12v with an inverter, or it may start with some completely different voltage. As I said, I have no experience with USB drives. But I barely have any devices that use AC adaptors that use the same voltage or even connector. Even that parallel Zip drive I bought last year doesn't use the same adaptor as the USB Zip drive I bought this year. Michael

Hactar (ebenZEROONE@verizon.net) writes: > The first method is a lot easier. If I were designing the case I > would probably specify 12V power, and then convert down if USB doesn't > supply enough 5V power. > But my argument is that the damage that can be done sets things up to be cautious. I've seen lots of posts elsewhere over the years of people connecting the wrong AC adaptor to a unit and doing damage. They lack the means of doing any sort of checking in the first place, and of course they completely lack the means of doing any repair of the damage. I'm not arguing about what is likely in there, I'm arguing that being careful should be formost. One can always try a 5v supply of proper polarity and current, and if that doesn't work, then try something higher in voltage. Witness someone suggesting the drives themselves may not need 12v, which I can imagine happening though there I also don't have experience with the latest hardware. There's hardly a point to a 12v supply if the drive itself doesn't need it. Design is often more complicated than the obvious. It's a tradeoff between function and cost, and sometimes what seems to be a bad choice turns out to be the better choice, when you look at the overall picture. If I was stuck with such a situation, a piece of equipment with a missing adaptor and no information, I'd be doing searches (the original poster said he did), and even then I'd likely try to trace things out to verify the information. (INdeed I did face such a situation, an older Mac Powerbook with no adaptor, no markings on the case. I did a search, found something, but didn't try it out until I at least checked to make sure the polarity mentioned was the same.) It's easier to be cautious in the first place than to assume something and learn you assumed wrong. Michael