External usb drives behaving differently

Forums › Desktop computing › External usb drives behaving differently

Rickles

1760 posts

Uber Geek
+1 received by user: 126

Topic # 92461 30-Oct-2011 08:46

I have encountered an odd problem.

I have two external hard drives, both 2.5inch but one is IDE (20GB) and the other SATA (120GB). Both work fine when cabled to my desktop or laptop.

However, when using a TV media player (NBox), only one drive is recognised by the player unit ... being the IDE drive.

Any ideas why the other drive will not show up?

I thought that power ratings might be the problem, but then the IDE is 5 volts and the SATA 3.3v, so the mains connected media player should handle that OK? Both are NTFS and seem the same other than size and brand of casing.

R.

robjg63

2627 posts

Uber Geek
+1 received by user: 502

Reply # 539195 30-Oct-2011 08:57

Do both or either of the units have an external power supply?
Could be the TV cant supply enough power via USB to power the drive???
It wouldnt be the voltage - USB always supplies 5v.
The wattage may not be enough on a low powered USB port to actually power a device though.
It would be enough for memory sticks and maybe a very low power consumption disk drive - but the lerger drive probably needs an external power supply connected.

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler

Rickles

1760 posts

Uber Geek
+1 received by user: 126

Reply # 539200 30-Oct-2011 09:05

Morning Rob,

Ironically, the IDE drive case has a power inlet, but I've never used it since the USB cable delivers enough for it to work. The SATA is pure USB cable driven.

Would the capacity of each drive have such a dramatic effect in this way ... they are afterall the same size platters, surfaces etc? Then again maybe the heads and electronics for the larger capacity drive work harder and need more power?

R.

robjg63

2627 posts

Uber Geek
+1 received by user: 502

Reply # 539202 30-Oct-2011 09:09

See if you can find out which device draws the most current. Id still guess that its that.

Do you have more than one USB port on the TV?

You could try one of those USB cables that has 2 plugs on one end and one on the other:
see http://wiki.answers.com/Q/Connecting_a_double_usb_cable_to_a_laptop
They look like this:
http://www.insidesocal.com/click/toshiba_usb_drive_with_double_USB_cable_550.jpg

You plug the 2 USB plugs on one end into 2 USB ports to get the juice from 2 USB ports

You can also buy "USB powered hubs" if power is the issue (put that into DSE.co.nz search and you will see what I mean). Most PC shops will probably have something like that available as well.

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler

Rickles

1760 posts

Uber Geek
+1 received by user: 126

Reply # 539205 30-Oct-2011 09:21

Rob,

Not using USB port on the TV, using an intermediate media player (so that I can display videos, pictures etc) on the TV via composite cabling.

Yes, I have the Y-shaped USB cables, but of course the media player has only one USB port.

I'm about to run the SATA drive out of its case using a powered adaptor ... I gues that will prove something .

R.

Rickles

1760 posts

Uber Geek
+1 received by user: 126

Reply # 539219 30-Oct-2011 10:11

UPDATE:

Removed SATA drive from casing and connected to a powered adaptor. Connected to the media player and away it went with no problems at all.

So, short answer is that the bigger capacity drive needed more power than the media player could deliver.

I wonder what the maximum drive size is before a single USB cable won't hack it?

R.

robjg63

2627 posts

Uber Geek
+1 received by user: 502

Reply # 539249 30-Oct-2011 12:08

I think the general rule of thumb is that anything larger than a USB flash drive - ie a hard drive should probably have an external power supply - guess some of the smaller laptop drive based ones might get enough power from a USB port - but dont count on it....

Nothing is impossible for the man who doesn't have to do it himself - A. H. Weiler