My Seagate external drive 9SD2A4 power light does not come on. I’ve tried using with other PCs and I still get no power (no green power light), how can I revive it and save my data?
If you are using a desktop machine, you can simply remove the drive from the existing housing and install it internally in your system. At least it will let you know if the drive itself is good or not and it does not cost you anything but a bit of time. If it works and you still want the portability, then you can look for another external enclosure.
well you have to buy the same hard drive as new then transfer the second one to the new
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Your best bet is to buy another portable enclosure, open the old (Seagate) enclosure and transfer the drive to the new enclosure. With any luck, the fault is in the enclosure and not the drive and all will be well. You'll need a 2.5" USB enclosure with in internal SATA connector. These are very easy to come by (e.g. on eBay) and very cheap.
If the problem is with the drive itself, you'll need to send it to a data recovery bureau. Unfortunately, recovering your data that way will be very expensive (hundreds or dollars, possibly more).