Nightmare Disk Failure & Recovery Attempt

RE: Nightmare Disk Failure & Recovery Attempt

dubbie — Wed, 11 Dec 2019 09:50:24 GMT

An alternative to a sharp bang would be to use a vibration, such as a washing machine on spin.

Dubbie

RE: Nightmare Disk Failure & Recovery Attempt

mcb1 — Tue, 04 Dec 2018 13:53:11 GMT

Both drives are powered via USB but these USB ports do not have power when the computer is off

Many of the USB ports are powered while the computer is shut down.

The BIOS sets some, and many computers utilise the 'hit any key' principle to wake them up.

Mark

RE: Nightmare Disk Failure & Recovery Attempt

mcb1 — Tue, 04 Dec 2018 13:47:37 GMT

I had an issue of 'killing' disks in my computer.

My son suggested they were subjected to overheating and provided a utility which showed they were not being adequately cooled.

This was soon solved with a Fractal R5 case where the drives sit across the front directly behind the fans. (comes with one but it is worthwhile buying the second front fan)

[View:/resized-image/__size/760x760/__key/commentfiles/f7d226abd59f475c9d224a79e3f0ec07-b488f0c1-2ca7-481d-ad26-bc15fde435a2/contentimage_5F00_205347.png:760:760]

The drives are now much cooler, and even temperatures rather than the hit and miss of the old case.

These cases are also whisper quiet, but do have a slightly bigger footprint.

Mark

RE: Nightmare Disk Failure & Recovery Attempt

jw0752 — Sat, 01 Dec 2018 18:51:12 GMT

Hi Douglas,

Congratulations on fixing something that wasn't supposed to be fixable. There should be a badge on element 14 for heroic efforts like this one.

John

RE: Nightmare Disk Failure & Recovery Attempt

glennvanderveer — Sat, 01 Dec 2018 15:26:17 GMT

Did you try entering the drive serial number on the manufacturer's website? You may even be able to get a warranty replacement for the drive itself. Although I wouldn't suggest adding a link to this video, just for warranty voiding sake...:-)

RE: Nightmare Disk Failure & Recovery Attempt

Gough Lui — Sat, 01 Dec 2018 08:58:02 GMT

Stiction is not uncommon between ultra-smooth heads and the surface. If the drive loses power due to a poor connection and there isn't enough back-EMF from the spindle motor and stored rotational energy in the spindle to force the heads to park back onto the ramp (through an "uncontrolled" unload), the heads will stay on the disk as the disk comes to a stop which creates the risk of the heads sticking to the disk so well that the spindle motor cannot overcome the force to unstick them.

This is something I saw several years back once ramp load-unload drives started hitting the market and were used in external cases. Sometimes people would let the drives partially spin-up and then unplug them - if the heads had been loaded onto the disk but the disk wasn't quite up to speed, often they could end up stuck. I have removed the top case and used a screwdriver to free the media from the head which was enough to get it going again for a friend. Of course, once violated, the clean atmosphere inside the disk is no longer guaranteed so the drive is not likely to remain reliable for long.

Others who are resistant to opening the drive have found that a good firm "slap" or drop can free the heads just enough for the disk to get going. However, it's a delicate balance - too much of a hit and you'll either chip a head due to the "slapping" motion, or cause disk shift (where the disks move relative to the spindle) causing run-out error instead.

The "beeping" noise is basically the spindle motor driver's "soft start" waveform into the motor coils, and its magnetostriction causing audible noise generation. Of course, with the monitored and current-limited condition of the motor driver IC, it will cut out and retry a fixed number of times before stopping until power is removed and cycled.

In older contact-start-stop (CSS) disks where the heads rest on the platters when parked, the inner tracks designated as a landing zone have laser texturing applied to them so as to make them less sticky, however, they had a much more limited takeoff/landing cycle life as the friction during the spin-up process gradually wore away at the sliders causing their aerodynamics to be slowly altered until they couldn't "fly" in a stable configuration or height.

- Gough

RE: Nightmare Disk Failure & Recovery Attempt

14rhb — Sat, 01 Dec 2018 07:39:27 GMT

Hi Douglas,

This is great work and should inspire a few others to have a go rather than accept their data is lost forever. I'm surprised you were able to get it going again, but am really pleased to hear you did.

Rod