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Windows 7: External HDD not dectected in PC

10 Feb 2012   #11
Kevin Ismail

Windows 7 Ultimate x64

Hi Tsram
Through all given advice above and what you had tried by combining power from other source (laptop) with your Y cable, it's pretty obvious that you have under voltage problem. It could be coming directly from the PSU, or voltage regulator on the MB, or, most of the capacitor handling USB voltage supply started to get dried. Trying to directly supply/combine the 5 volt on your USB cable from the PSU is not advisable as it may interfere the MB voltage regulator. the USB voltage is delicately regulated. It is used to manage the USB device when connected/disconnected. Its true if you see some USB HDD come with 5 volt external adapter but it's mainly to help spinning up the disk plate and it's isolated from the USB port.

In normal way, you will have to try replacing the PSU with new one (or borrow one if just for testing). If it doesn't work then you may conclude that the MB is almost out of service though it works for the mean time.

But one thing. You haven't mention it was rear or front USB panel. If it was front, then try with the rear panel.

Hope that help you some.

My System SpecsSystem Spec
10 Feb 2012   #12

Windows 7 Home Premium 32 bit

If the HDD/s did come with a Y cable, then the manufacturer knows that such devices inherently draw a higher power and that some systems may not be able to to deliver that.

So my advice will be if the HDD did come with a Y cable, use it and be happy.:)

That said I am just curious to know which HDD is it?

I have all Seagates only and they all have only a single ended USB cable.

Only my USB external BD writers come with a Y cable, since burning requires more power. I will be producing coasters if I do not use the Y cables provided.
My System SpecsSystem Spec
10 Feb 2012   #13
Hopalong X

Windows7 Pro 64bit SP-1; Windows XP Pro 32bit

The HDD worked when I used a Y cable( 2 usb male ports). I connected the Data port to my PC and power port to my laptop.
I agree with Kevin Ismail.
In your above statement the laptop is powering the HDD.
Power supply or motherboard not providing enough voltage.

As stated already try a different PSU or have the PSU tested if possible.
My System SpecsSystem Spec

10 Feb 2012   #14

Windows 7 Home Premium 32 bit

Yes, if the HDD you use didn't come with a Y cable , it should work with the single-ended cable.

In the event even those which came with a single ended cable do not work, then as I mentioned in the first post either your Power Supply or Motherboard is suspect.
My System SpecsSystem Spec
10 Feb 2012   #15

Windows 7 64 bit

Looks like power shortage then. I can't just cange teh Mb now.(Even if its the problem maker).

I can either go for a new PSU or look for a Externally powered USB hub rite.
I can get good powered hubs for Rs. 800/- (From belkin) but If I go for PSU I will have to get some avg standard ones so it will be around 3500/- + .
Will it be worth spending for PSU? I mean all my other stuff are going ok. I am not planning in overclocking, I don't go peak load most of the times. So the PSU won't get me any performance boost.
Should i just go for a Powered HUB?? Is the PSU worth it?
My System SpecsSystem Spec
10 Feb 2012   #16
Hopalong X

Windows7 Pro 64bit SP-1; Windows XP Pro 32bit

If money is a big concern then a powered hub may be the best idea.

A powered hub is always useful for use on any PC/laptop.

Your choice.
My System SpecsSystem Spec
10 Feb 2012   #17

Windows 7 Home Premium 32 bit

Take it to a Computer service professional/ your motherboard manufacturer's service center ( if available at your location) and ask them to substitute the Power Supply/motherboard and check, before blindly buying a new power Supply or motherboard. ( Personally I would not recommend any workarounds. To be safe the defective part should be replaced.)

Are not the PS and motherboard under warranty?
My System SpecsSystem Spec

 External HDD not dectected in PC

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