Cannot get my computer to read Hitachi H3640US hard drive. Power on at drive and light on, but when connected computer does not recognize. When I turn drive on, the light does not cycle.

would this help ...
Resources HGST
Look for the list of EOL disks and figure out which of those is a match your disks

Hitachi External USB Storage Quick Start Manual Page 2

A Hitachi USB external hard drive is a device that acts as portable, removable storage for your personal computer. If you need additional space to house files on your computer but don't want to go to the trouble of installing an internal drive inside the case, a USB external hard drive is your best option. These drives are "plug and play" devices, which means that very little can actually go wrong. If you're having problems, fixing them shouldn't take more than a minute or two.

Check your connections. A USB cable needs to be connecting your Hitachi external hard drive to your computer. Your external hard drive's power cable also needs to be plugged into a functional wall outlet, surge protector, extension cord or power strip. Make sure your Hitachi USB external hard drive is turned to "On." An "On/Off" button is present on the front of the unit. If the indicator light around said button is not illuminated, the drive is "Off" and your computer won't be able to recognize it. Press it to turn it on and then try to access your drive again. Format your hard drive. If your Hitachi USB external hard drive doesn't currently have a file system on it, you won't be able to use it to store data. Open up the "Computer" icon in the "Start" menu. Right-click on your USB external hard drive's icon and click "Format." Click "Start." This will install a file system on your Hitachi USB external hard drive. After this process is finished, you will now be able to use your drive. Restart your computer. Certain models of computers (especially older models) won't recognize new hardware unless your computer boots with the hardware already connected. Leave your USB drive plugged in and restart your computer. Once you do this, your Hitachi USB external hard drive should appear as normal in the "Computer" folder with all of your other drives. Hope this helps.

A Hitachi USB external hard drive is a device that acts as portable, removable storage for your personal computer. If you need additional space to house files on your computer but don't want to go to the trouble of installing an internal drive inside the case, a USB external hard drive is your best option. These drives are "plug and play" devices, which means that very little can actually go wrong. If you're having problems, fixing them shouldn't take more than a minute or two.

Check your connections. A USB cable needs to be connecting your Hitachi external hard drive to your computer. Your external hard drive's power cable also needs to be plugged into a functional wall outlet, surge protector, extension cord or power strip. Make sure your Hitachi USB external hard drive is turned to "On." An "On/Off" button is present on the front of the unit. If the indicator light around said button is not illuminated, the drive is "Off" and your computer won't be able to recognize it. Press it to turn it on and then try to access your drive again. Format your hard drive. If your Hitachi USB external hard drive doesn't currently have a file system on it, you won't be able to use it to store data. Open up the "Computer" icon in the "Start" menu. Right-click on your USB external hard drive's icon and click "Format." Click "Start." This will install a file system on your Hitachi USB external hard drive. After this process is finished, you will now be able to use your drive. Restart your computer. Certain models of computers (especially older models) won't recognize new hardware unless your computer boots with the hardware already connected. Leave your USB drive plugged in and restart your computer. Once you do this, your Hitachi USB external hard drive should appear as normal in the "Computer" folder with all of your other drives. Hope this helps.

ry connecting the external hard drive to another computer to recover/backup your data.
When you have such a large capacity hard drive, it pays to have a second large capacity hard drive to backup your data in the event of the other hard drive dying.Hard drives do fail especially if you accidently drop it.

i just woke up to the same problem this morning ... i believe my drive has went out

As long as you are sure the hard drive is connected properly with SATA cables to the motherboard and has power from the power supply unit, and that the drive is working, you can enter the BIOS on computer startup and modify the "boot device" look in "primary boot device" for a name matching that of your hard drive (probably "HITACHI .....) If it is there select it as the primary device and hopefully it will boot and ask you to install windows. If it is not there the drive may not be connected or it may need to be replaced. Hope this helps!

Try another cable and make sure the connection is in all the way. Also try it on another port or computer. If you need more help, please call HitachiGST Tech Support M-F 8AM to 6PM PST at 1.888.426.5214 and a technician will be happy to help you.

Look at the "connectors" end of the disk-drive.
There will be a set of thin pins for the "data" cable,
and thicker pins for the "power" connector,
and a smaller grid of small pins.
It's these pins that will be labelled/engraved on the casing:
MA(ster), SL(ave), C(able)S(elect).
Move the jumper to the "slave" setting.
Connect to the power connector.
Connect to a "data" cable.
When you add power to your computer, it should recognize the drive.

did you format the drive yet?

Try plugging it into the back ports of your computer haven't already. The clicking is from the reading head not finding zero on the platter, which means its either a bad drive or a lack of power. So try the back ports first if you haven't already, because they usually supply more power than any front ports. It also depends on how old your computer is, but in general if it has XP on it it should have enough juice to power the drive.