Computer Not Recognizing External SEAGATE STEA2000400 2TB Disk on USB2.0/3.0: Troubleshooting Tips

Hello.
I was looking and what I found did not help.

I have 2 situations:
1. External disk SEAGATE STEA2000400 2TB 2.5 "plugged in USB3.0 and compatible with USB2.0. After connecting to an older laptop (DELL D630 WinXPPro SP3 internal drive 500GB divided into 4 partitions USB2.0 output) external disk:
- lights up the power light
- information on the bar appears that an external USB device has been detected (it did not appear that the device is ready for use)
- it is not displayed in My Computer
- you can not see disk management at all
- Device Manager sees "Seagate Expansion USB Device" without any exclamation points (in the properties does not show any volume)

After connecting to the Win7Pro SP1 desktop, internal SSD250GB + HDD1TB drives, USB3.0 and 2.0 outputs:
- lights up the power light
- information appeared on the bar that an external USB device was detected and that the device was ready for use
- it is not displayed in My Computer
- you can not see disk management at all
- Device Manager sees "Seagate Expansion USB Device" without any exclamation points (in the properties does not show any volume)

2. SSD ADATA SD700 512GB external drive. The new Win7 desktop computer can see it both on USB3.0 and 2.0 and you can do anything. I divided into 2 partitions of 250GB. Old DELL unfortunately:
- does not display the disk (partition) in My Computer
- in disk management you can see this disk without an assigned letter as one partition (476 GB Protected GPT partition) - you can not assign it to the letter (options are inactive)
- in the device manager the disk can be seen without the exclamation marks ADATA SD700 USB Device, but the properties do not show any volumes
- of course, the power is on

USB efficient other devices or disks work.
Replacing the wires does not give anything so smooth.
I thought the problem was the capacity, but I connect another WD My Passport 500GB 2.5 "drive and computers can easily recognize it, DELL assigns it letters I and H and everything flashes.

Turning off in the device manager does not help.
Updating drivers is writing that they can not install anything better.
Both disks new straight from the store.

Does anyone have any idea what else to check or some theory?
Because I come to the conclusion that the 2TB hard drive is damaged, and the 500GB SSD is new for old DELL although I do not know why.
I'm still thinking about powering USB ports if it's not too weak. But in Win7 it supplies SSD500GB so why HDD2TB would not go.

Domelski wrote:

I'm still thinking about powering USB ports if it's not too weak

Use a USB type cable Y ".

Domelski wrote:

But in Win7 it supplies SSD500GB so why HDD2TB would not go.

For example, because the current consumption of a disc disk is much larger than that of SSD.

That's how I plan. That I will ask you a little laicko. Can I then connect the Y cable simultaneously to USB 3.0 and 2.0. I mean, if the data can go 3.0, and the additional departure from 2.0 only power, do they have to be 2 identical ports? I do not know how exactly this wire works, but for logic, data goes only one entry.
I do not know if the USB outputs will bite then.

On the other hand, the manufacturer gives one USB3.0 cable and are the USB3.0 outputs not standardized in terms of current efficiency?

You can connect the Y cable to USB 3.0 and USB 2.0 not at the same time. Remember that each USB port has a separate power supply, which is why there will be more current efficiency of such a set.

There is no data line in the extra wire, so it will not bite.

Remember that the thicker one was under USB 3.0, then the data will be sent at a higher speed.

Windows 7 does not properly view the disk with the gpt partition table, use the disk management program and change the partition type from gpt to mbr and partition it if necessary.