Hard Drive not visible on my laptop

Would be great if the next time you also place the model number, because Cavalry makes dozens of different drives.
When the bleu light does not go on, you have to assume the drive is not getting power.
If the drive has only one cable, (small drives like 2,5 inch most of the time only have one cable) it could be the USB cable is defect and can't give through the 5 Volt coming from the computer USB connector. It also could be the 5 Volt supposed to be in the computer has gone.
If you have to connect an external power supply, with a small cable to the drive, I would check the power supply. A 5 Volt 2 A supply, with the round plug can't be that expensive.

If both don't work, it also could be inside the housing of the drive is something defect.
If you need to have the data on the drive, you always could but an universal USB connection for hard drives. I have one for IDE and E-SATA, in the box came a set power cables and a power supply, but that one was almost 50 dollar. There are cheaper ones on the net.
Be aware drives don't live forever and make sure you always have at least two backups. (that is more than one origin; and one back up)

1. This could be due to several things.
a. The power supply for the external drive is not working properly
b. A broken power supply connector.
c. The USB drive was disconnected improperly > that is not disconnected safely in Windows
d. The external drive controller in the USB case is defective. A new case is needed.

see if this link helps you out.
formatted faults Google Search

http://www.fixya.com/support/r4247716-usb_device

Check ther for most of the simple and common fixes

Bob

All you need to do is to follow the instruction to format the drive then try a know good USB cable to work. Thank you.

Hi,
Do you want to format your C:?
if you want to format just insert a bootable windows service pack 2. It has a format option installing a new windows.

Or if you don't want to format because there is an important file..

insert windows service pack 2. then there is an option before the format if you want to repair or configure your old Operating System. You can access there. its default location is C:\WIndows\...

Keep them in the freezer for 3 hours and connect to your system and transfer your data. If drive starts behaving like this, it means you have to transfer the data.

First I had to reseat one of the drives which had worked loose and become unseated during shipping. Then I had to format the hard drive and finally I had a 1TB external hard drive I could use. The light is still red.

Just change ( buy ) new external then put hdd on new external and everything will work fine!

head crashed is the most likely reason.
drive has lost its directory and boot segment address.
you have lost your drive functionality.
the drive would need to be much larger than average to bother fixing, but if you need the data, then you can send it in for repair. expect 500 to 2500 for data recovery/repair.
sorry for the news.
mark