Primary Hard Drive instability and 1 second Blinking HDD indicator LED

Hello everyone,

I have had huge issues with my custom made computer recently, I have never have had any issues with my Hitachi HDS721050DLE630 (OS HDD) until today, last night, I defraged my computer last night, and today, I've had 4 critical hard drive failures / hangs... On the first failure, the hard drive stated making a strange noise on and off for a minute, the entire time all applications and services stopped responding, including Adobe Premiere Pro CS6, which I suspect was part of the cause, in fact, the stopped responding error stopped responding... I attempted to ctrl+alt+delete my way out of the problem, but that threw a silent error, right click on the desktop made the Windows Explorer desktop process stop responding, pressing "all applications" in the start menu made the start menu stop responding, the HDD indicator LED stopped going on when the HDD was in use and started flashing for a short period of time followed by a 1 second pause, and all this continued going on for five minutes (until I held down the power button). In which time Adobe Premiere worked for a few seconds, but didn't save any work that wasn't already saved before the ordeal. And, to top it all off, after successfully booting up the computer, the System Log only had history of a reported event where the kernel wasn't shut down successfully... The next 3 times ranged from 20 minutes to 1 hour of working perfectly fine, but then the same issue, but without the hard drive making the strange noise it did the first time...

Now, the HDD indicator LED flashes on and of with 1 second intervals like it was when the failures had started, but it also now goes on when the HDD is active, and I haven't had any critical failures since...

Any sugestions on what I can do to find out what I could do to figure out what's going wrong / what I can do to fix it?

Usually I'd ask about SMART readings and such, but given your explanation of the situation you're in I will cut to the chase.

IMMEDIATELY backup any critical data you have, your current HDD (the Hitachi) is on its last legs and judging from what you've experienced it's highly possible that HDD can die at any moment. I cannot stress this enough, IMMEDIATELY backup any critical data you have.

Once you have your data secured so that you don't suffer from data loss, look into replacing that HDD ASAP. HDDs do not make significant noise during normal operations, as such the "strange" noises you heard are abnormal and a tell-tale sign that something is wrong. If the "strange" noise that you heard was similar to a "clicking" sound, then that is a definitive sign that your HDD is on the brink of dying.

What I believe happened, judging from your explanation, is that the HDD was already on the fringe of being on its last legs but the defragmenting operation that you performed finally pushed it over its limits. A HDD defragmentation operation is very intensive and places more physical stress than usual on your HDD.

Again, IMMEDIATELY backup any critical data you have so you don't suffer from data loss. Securing your data is of the utmost priority right now. We'll be happy to help you with replacing the HDD, but we need to get more important things out of the way first.

Ok, I'm running backups now, but I do want to stress that the computer has been continued to be used as an attempt to recreate the issue, but it hasn't failed again.

Au though it has started to make the noise again, I can only describe it as quiet for one second, then a constant humming sound for a sound, progressively getting louder, then quieter. I do have a recording of the sound on my phone, but it isn't a very good quality recording, (it's far clearer and softer in reality)... Here is an upload here. No clicking, but a regular noise and HDD indicator flashing, do you know if the hardware would use the HDD indicator LED to show errors?

I believe your reason for the issue is correct, the defragment I performed earlier didn't appear to be problematic, but it is pretty much the only constant in all 4 of the incidents.