Lamp0 653 Posted December 5, 2018 I pulled a disc drive from an old laptop, I got a case for it with a USB 3.0 to micro USB connector and it works great. I found the cable is a little short, so I bought a longer, 9 foot one. But using this new cable to connect the disc drive with my laptop(windows 10) doesn't work. It gives a "USB device not recognised" message. Yet using this new cable to connect the disc drive to my old desktop(Windows 10) works fine. The new cable also works fine connecting an external hdd/ssd to my laptop. And the cable for the external HDD/SSD works fine in connecting the disc drive to my laptop. So I am confused, is this a bad cable or is there a compatibility thing I am missing? Thanks! Share this post Link to post Share on other sites
Jim K 14,928 Posted December 5, 2018 Could be the USB ports on the notebook deliver less power than needed by the external HDD over that length of cable. You could use this program on both the desktop and notebook to see how many milliamperes the port(s) can supply. If the notebook is noticably less...that could be the problem. https://www.nirsoft.net/utils/usb_devices_view.html This is just a hunch since the HDD works fine on a shorter cable ... and works fine on the desktop with a longer cable. 1 Share this post Link to post Share on other sites
helpifIcan 45 Posted December 5, 2018 I have had this problem on my DT using a long extension cable for my external drive. So it is an issue with the cable length. I got a shorter one and the problem went away. Not saying that will work for you just to let you know this is a known issue with cable length on some MBs be they DTs LTs. 1 Share this post Link to post Share on other sites
Brandon H 3,632 Posted December 5, 2018 my guess is the same as Jim's I'd bet the laptop usb port isn't providing enough power over that length of USB cord it's not too unusual for laptop usb ports to be undervolted to save battery power so it's definitely possible; sometimes on newer laptops that do this there will be 1 usb port that's not undervolted and is dedicated for providing power but that port is usually marked when that's the case 1 Share this post Link to post Share on other sites
Lamp0 653 Posted December 5, 2018 43 minutes ago, Jim K said: Could be the USB ports on the notebook deliver less power than needed by the external HDD over that length of cable. You could use this program on both the desktop and notebook to see how many milliamperes the port(s) can supply. If the notebook is noticably less...that could be the problem. https://www.nirsoft.net/utils/usb_devices_view.html This is just a hunch since the HDD works fine on a shorter cable ... and works fine on the desktop with a longer cable. Of course! That make sense. Also, I don't know why I wrote "disc drive" I meant "optical drive". I gave that program a go, and if I am reading it correctly the desktop is giving out 500mA to the external optical drive, where as the laptop is giving 144 mA to it. Is there any general advice about cable length for connecting higher power devices to laptops? The cable it comes with is about 1.5 feet. Thanks for all the help! Share this post Link to post Share on other sites
Brandon H 3,632 Posted December 5, 2018 no guides that I'm aware of but there are USB cords you can get that have a powered repeater on it specifically for running things longer distances. should work well for what you need; here's a few from amazon for you https://www.amazon.com/s/ref=nb_sb_ss_c_1_14?url=search-alias%3Daps&field-keywords=powered+usb+repeater&sprefix=powered+usb+re%2Caps%2C159&crid=2R2ZEP59G8OSB edit: since you said you're using USB 3.0 here's a couple specific from the listing: 5 Meter (16 Foot) USB 3.0 Active Extension Cable with AC Power Adapter 10 Meter (32 Foot) USB 3.0 Active Extension Cable with AC Power Adapter Share this post Link to post Share on other sites
