I connected a 1TB 3.5" HDD with a breakout cable to my notebook. When I start the notebook, the HDD is not spinning up nor is it getting recognized. I toggled the Bios options AHCI on/off and LBA to Dos/other, with no success. Could it be that the sata power connector on notebooks only delivers enough power for 2.5" HDDs?

Technically everything is working fine. Usually I use the notebook with an SSD. A 2.5" HDD connected to the breakout cable works. The 3.5" HDD connected to my desktop PC works. I'm getting a couple of old HDD ready to sell through ebay. Having a 2nd PC to test and delete would be very useful to me.

Notebook with breakout cable and 3.5" hdd

  • That sounds possible - maybe try it with another 3.5 inch hdd on the laptop?
    – Journeyman Geek
    Jan 11 '15 at 12:06

Most 2.5" HDDs only need the 5V power rail from the SATA power cable to fully function. If you look at any portable HDD that's only powered by USB you'll see there's no additional power cable and they're only ever 2.5" disks; because USB only provides 5V. Yes, some disks come with a USB "Y" cable for additional power but this is for additional current, not voltage.

3.5" HDDs require both 12V and 5V power rails. Again, the desktop 3.5" HDDs usually come with (or require) an external power source because the USB connection itself cannot provide enough power.

I will guess that your notebook SATA does not have the 12V power because it does not ever need to power a 3.5" HDD.

  • Yepp that sounds logical
    – mles
    Jan 11 '15 at 13:16
  • 1
    @mles you can make it work as long as you also connect a 12V SATA power connector from a desktop PSU. Only the data cable (flat red in your picture) needs to be connected to the laptop. Btw you can also use a 3.5" USB enclosure which comes with a power supply adaptor. A laptop BIOS can usually boot from USB-connected hard disks.
    – ADTC
    Jan 12 '15 at 0:12
  • I know, I've already ordered a Sata extension cable. I do have an USB enclosure, but I need the HDD connected directly by SATA.
    – mles
    Jan 12 '15 at 9:59
  • You can connect it directly, you just need the SATA power portion provided by a mains supply. The data portion is simply a male to female extension. I've tried to do exactly what you're doing and the male to female extension is difficult to find lol!
    – Kinnectus
    Jan 12 '15 at 18:32

I have a setup like the following, which you can use on any computer with a USB interface. It's a quick way to access the HDD data, and/or in your case, check if the HDD is operational. This one in particular comes with an external power supply, that will solve your HDD power issue. http://www.amazon.com/gp/aw/d/B000YJBL78/ref=redir_mdp_mobile/187-1856126-8349458

  • I have a similar one like that, but I wanted to connect the Hard Drive directly to the board by SATA.
    – mles
    Jan 11 '15 at 19:32

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