External USB disk not recognized on power up

Robert Carnegie

2012-01-07 15:14:11 UTC

Post by Raj
Experts,
I just installed Windows 7 x64 on my Latitude E6420. To this I
connected an external Signature Mini 250GB USB disk, using 2 Y USB
connectors, both plugged into the laptop. The moment I plugged in the
USB connectors, the disk is recognized and all is fine.However, when
I shutdown (power down) my laptop and then restart it, the disk does
not appear. I have to physically unplug and replug the USB connectors
for
the disk to appear.
If I just reboot the machine (without a power down), the disk is
still recognized. I checked the drivers and all of them seem to be
current and fine. What do I have to do, so I don't have to unplug and
replug the USB connectors after every power up?
Appreciate your help on this.

Did this work before you installed Windows 7 x64?

Things to try:

(1) I think you're describing a lead with one USB data connection and
one that only takes power from a USB port. Maybe you only need to re-
plug the data connector. They may be labelled "Data" and "Power".

(2) Use the disk drive with an externally powered or battery powered
hub, and switch it on first.

(3) If you have more than 2 USB ports, ports that are not next to each
other may be less likely to be sharing the port power supply.

(4) You might get away with plugging the power-connector into a port
on the laptop's charger, or into a separate battery with a USB port -
there are a few on the market.

(5) You could reboot the laptop more slowly, to give the external disk
more time to become ready. Press F8 to pause starting Windows, or
whichever key opens the boot device selector, or BIOS settings editor.

(6) Perhaps the dsk drive has an additional power port.

(7) You could get another external disk that only uses one USB port.