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Low power on USB ports?
Posted: Mon Mar 14, 2011 4:35 pm
by Lars
Is it possible that power on the USB ports on an X60s is unusually low?
A friend has had problems connecting his Samsung Galaxy S smartphone to his X60s.
The software Samsung Kies just sits there with an icon indicating "connecting" but it
never seems to complete the connection.
So we tried it on my X60s with the same poor result.
Then I have installed the same drivers and software on other Thinkpads.
T42 works fine, X61 fine, X41 fine, X31 fine. All of these machines has Win XP SP3.
Only the X60s will not connect.
I have tried all three USB ports on it, same poor result.
All machines are plugged in to power brick and have fairly good batteries.
Re: Low power on USB ports?
Posted: Tue Mar 15, 2011 9:19 am
by EOMtp
Standard output on USB ports is 5vdc/500ma, and your Samsung device requires >500ma. Perhaps some USB ports on some machines deliver higher current than 500ma, but one should not expect that as a general case.
A USB Y-power cable, similar to the one shown below, with the correct connector for your Samsung, will solve the problem of delivering >500ma:
http://cgi.ebay.com/USB-2-0-2-Male-mini ... 1c1a188de8
Re: Low power on USB ports?
Posted: Tue Mar 15, 2011 3:23 pm
by yak
Does a mobile phone even need the power from USB? It's not like it doesn't have its own battery.
It should only draw power for charging (assuming it has such a feature).
Re: Low power on USB ports?
Posted: Wed Mar 16, 2011 4:35 am
by EOMtp
yak wrote:It should only draw power for charging ...
Yes, that is true. Still, who knows what that unit expects when connected to a USB connection?! Since the original question asked about "power", I thought he should know about what "power" is available via USB. I agree with you: "seeing" the device should be possible if the device has its own charged battery.
Re: Low power on USB ports?
Posted: Thu Mar 17, 2011 2:56 pm
by Lars
EOMtp wrote:Standard output on USB ports is 5vdc/500ma, and your Samsung device requires >500ma. Perhaps some USB ports on some machines deliver higher current than 500ma, but one should not expect that as a general case.
A USB Y-power cable, similar to the one shown below, with the correct connector for your Samsung, will solve the problem of delivering >500ma:
http://cgi.ebay.com/USB-2-0-2-Male-mini ... 1c1a188de8
I don't know for sure why one particular model Thinkpad is unable to connect
to the Samsung phone when several others 'connect' fine, both older and newer
model Thinkpads.
I was only guessing it may be not enough milliAmperes. Hence my question.
I checked the leading computer stores here for a Y-cable with USB micro contact
in one end, but found none. So I bought two single USB to USB-micro cables, cut
them open and spliced together. That did not work out at all. Windows popped
up messages about USB devices not being recognized etc.
It seems that there is more to Y-cables than I knew.
On some American web-shop I have seen a Y-cable that may be what I am looking for
but with some of them I am not entirely sure whether the small plug is mini or micro.
Re: Low power on USB ports?
Posted: Fri Mar 18, 2011 10:31 am
by EOMtp
Lars wrote:... two single USB to USB-micro cables, cut them open and spliced together. ...
You must NOT splice the data lines, pins 2 and 3. Splice ONLY the power lines, pins 1 and 4. Once you do that, you will at least have ample power ... and if the device is still not seen, at least you will know that it is not because of insufficient current.
Good luck!
Re: Low power on USB ports?
Posted: Tue Mar 29, 2011 3:53 am
by Lars
EOMtp wrote:You must NOT splice the data lines, pins 2 and 3. Splice ONLY the power lines, pins 1 and 4. Once you do that, you will at least have ample power ... and if the device is still not seen, at least you will know that it is not because of insufficient current.
Thanks. It seems not to be a problem with insufficient power.
I have given up on this.