I encountered a problem while trying to upgrade an old (10+ years) Samsung NP300E7A-S01IT laptop's HDD into a newer SSD.

I bought the SSD (Samsung 870 EVO 1TB 2,5" SATA III SSD MZ-77E1T0B/EU) and cloned the HDD (Hitachi 640GB 2,5'' SATA II HDD NP300E7A-S01|T ) into the SSD. But when I installed it onto the laptop, the BIOS wouldn't see the hard drive (wouldn't be listed in the bootable devices and the SATA slot was listed as empty).

The laptop is a Samsung notebook model NP300E7A running Windows 10 Pro.

What I tried to do:

  • Resolve boot problems with the Windows 10 installation media.
  • Hook the cloned SSD to a USB to SATA connector. The laptop booted into Win10 but then Windows showed an error "Device inaccessible"
  • Formatted and cloned the SSD again.
  • Changed the cloned SSD from MBR to GPT and vice versa.
  • Checked for driver updates
  • Checked if the SSD is faulty. The SSD seems perfectly Healthy
  • Forced AHCI on
  • Switched back to the old HDD and back again to the new cloned SSD. The laptop booted normally with the HDD, but the problem persisted on the SSD

I suspect the problem may lie onto the connector since the SATA connector lacks some pins as you can see in the first picture below.

Additional images can be found here.

It's seen here that the SATA power connector lack some pins

Original HDD with label.

Here is the SATA connector alongside the original HDD.

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  • 1
    Have you checked for compatibility at a vendors' site, such as Crucial, crucial.com/store/advisor , or Samsung, samsung.com/us/business/products/computing/ssd/finder/# ? Jan 6, 2023 at 20:43
  • If the SSD could not be seen by the bios what did you do with the Windows install disk to fix the problem? The install disk should not be changing bios settings.
    – doneal24
    Jan 6, 2023 at 21:01
  • 1
    So (to simplify) the power portion of the laptop connector is missing 3v which is fine, the next 6 pins are 5v and the rest would be expected to supply 12v. Your Hitachi says 5v on it, it is unclear after very quick glance if the EVO needs power on the (missing) 12v pins
    – Yorik
    Jan 6, 2023 at 21:01
  • I thought 2.5 SATA was implicitly 5v, but would not testify to it.
    – Yorik
    Jan 6, 2023 at 21:05
  • @DrMoishePippik I did not check with the samsung tool. However checking with it now shows that the Samsung 860 Evo would be compatible, but with a quick search I am not able to discern the differences between the 860 and 870 Evo. Why would the former be compatible and the latter not? I did use the crucial tool to see if the laptop would support any SSD at all, but I only found this, which was not too specific.
    – FBeno
    Jan 7, 2023 at 11:32

2 Answers 2


Looking at a detailed Samsung 870 QVO SATA SSD, not the model you specified, Data Sheet from 2020 it seems Samsung are using the SATA power pins you are missing for device operation.

I think it is highly likely your EVO model is the same. It states the 2020 870 QVO is SATA 6.0Gbps and that it “Partially complies with revision 3.3” of the SATA specifications.

Specifically they have connections and support for pins P3 through P12 while your device only provides for P4 through P9.

I submit that your SSD will not operate without connections to these pins.

Page 11 Samsung Data Sheet Electrical Interface Specification

P1 Reserved No Connect (Reserved for future use)

P2 PERST# No Connect(PCIe Only)

P3 DEVSLP Enter/Exit Device Sleep

P4 IFDet Interface Detect, 1st mate

P5 GND Ground, 2nd mate

P6 GND Ground, 2nd mate

P7 V5 5 V power, pre-charge, 2nd mate

P8 V5 5 V Source

P9 V5 5 V Source

P10 GND Ground, 2nd mate

P11 DAS/DSS Device Activity Signal / Disable Staggered

P12 GND Spin-up Ground, 1st mate

P13 V12 No Connect (12 V power, pre-charge, 2nd mate)

P14 V12 No Connect (12 V power)

P15 V12 No Connect (12 V power)


  1. Uses 5 V power only. 3.3 V and 12 V power are not used
  • Pin 3 works the opposite way. If high, the device is disabled. It is not connected (missing on the laptop-side connector), so not high.
    – Daniel B
    Jan 11, 2023 at 9:25
  • So it does. Sorry, think my answer is useful at all, or can be modified to be useful, or would you delete it? Removing the section on P3 now.
    – Qribak
    Jan 11, 2023 at 9:31
  • @Qribak I see. So the lack of pins might be at fault here. May I ask if you know of an SSD model that might work with those pins only? Or if you know where i could find it?
    – FBeno
    Jan 12, 2023 at 17:45

The solution was to do a fresh installation of Windows 10.

Cloning wasn't enough since it couldn't make the laptop recognize the SSD.

What helped was to start a Windows 10 installation from another PC and when the installation finished but before the reboot, mounting the SSD onto the laptop.
After that the laptop succesfully recognized the SSD and booted Win 10 from it.

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