Why does this happen with USB ports?

[BuckMaster]

I had a D600 laptop with 2 USB ports. At anytime I could plug a external drive up to it and it would see the drive right off the bat then I could access it.

Now a Friend were I work has the same laptop and when he would plug my external drive up to his D600 laptop it "wouldnt" see it till he rebooted.

I just upgraded to a D620 laptop which has 4 USB ports. Now when I plug my external drive it doesnt see the drive unless I reboot?

Cany anyone tell me why this happens and if there a way it can be fixed to plug and play and see the drive while the laptop is already on without rebooting? Actaully I can just log off and back on and it picks up.

Thanks!

 

[Trey22]

Same problem w/ my 600m. Haven't found a fix for it yet.

 

[piasabird]

Not all devices for USB are Plug and Play.

 

[corkyg]

Is the external drive self powered? If not, it probably won't show on a laptop - USB power is insufficient for most external drives.

 

[BuckMaster]

Not all devices for USB are Plug and Play.

I know what your saying but I had a D600 that picked up the external drive just fine, then my friend had the same model D600 and didnt pick it up unless he rebooted or logged off and back on. Both devices being the same. Both have same setup and power adapter.

Is the external drive self powered? If not, it probably won't show on a laptop - USB power is insufficient for most external drives.

Again I know what your saying but doesnt make since. The external device is small external case with a laptop drive and just runs off the USB port. I thought also it may lack the insufficient power but why does it pick it up after I reboot or logoff and back on then?

Im on a mission here and just has me puzzled I guess.

 

[corkyg]

Originally posted by: BuckMaster
The external device is small external case with a laptop drive and just runs off the USB port. I thought also it may lack the insufficient power but why does it pick it up after I reboot or logoff and back on then?

Could be that it grabs the available power on reboot first. Anyway - I have played with this for the past year, and it is easily solved by connecting a 5 VDC power module to the external case. Believe me, it works.