USB drive isolation

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My daughter’s power supply died in a flash taking the video card, and both system HDD and backup HDD with it. All her nice image backups are gone. Is a USB external drive isolated enough that it would probably survive such a disaster or should I have done backups to separate computer or the cloud ?

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The logical answer to this one is, “Why don’t you try it out?”
Any other answer is pure speculation.

BATcher

Plethora means a lot to me.

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A USB drive will be isolated enough if, and only if, you unplug it from the computer when you are not using it! HTH :cheers:

May the Forces of good computing be with you!

RG

PowerShell & VBA Rule!
Computer Specs

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I second RG’s response. In addition, unplug the external drive’s power supply, so it won’t get fried if your house is hit by lightning.

Consider backups to the cloud (in addition to the local external drive) as a secondary, not primary, solution.

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My daughter’s power supply died in a flash taking the video card, and both system HDD and backup HDD with it. All her nice image backups are gone. Is a USB external drive isolated enough that it would probably survive such a disaster or should I have done backups to separate computer or the cloud ?

As RG states, at least one of your main backups drives should be external, kept separate, and only used when modifying and backing up.
Which means that it should remain disconnected when not in use for the above purposes.

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Thank all of you for your responses. I should have been able to figure that out myself but I am slowing down for some reason (82 years old now). To Batcher, I am not sure I want to risk a functioning USB drive to test it. The logic of unplugging the USB drive except when actually using it makes sense but would be at risk to my degree of attention. The combination of USB external drive and cloud is certainly best. I, myself use a network connected server for backups but it is at risk to whole house surges like lightening, so I will now arainge cloud backups for irreplaceable data.
RWC

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You could solve the problem by getting two drives, but only keeping one connected regularly.
The other, you would just have to remember to keep current, but separate.

The chances of a power supply taking out your external drives are pretty remote at any rate.

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I once experienced a failure where I assumed exactly what you state. Further investigation revealed that it was the reverse that caused the failure. In my case it was the video card that took out the other components, (perhaps???), ???. Hmmm, yet even further investigation revealed that the HDD was not destroyed at all. It was very recoverable. In order to find the HDD drive was still good, I removed it from the destroyed computer and placed it in a portable USB enclosure which allowed it to connect to a USB port. The OS was not functioning this way, but all else was available and recoverable.
Just saying, perhaps???
Michael

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Hi All:

I’m surprised no one also mentioned that you should always use a known good surge protector. If you had one before, its probably blown, too, so replace it with a heavy duty model. At the risk of some additional cost, you might also want to consider adding a UPS (uninterruptible power supply) of sufficient size to allow not just some additional surge protection, but also the ability to run for some period of time during loss of utility power. I have a 750kWA (overkill size!) on my system(s), which is enough to run both my desktop PCs, KVM switch, LCD monitor, DSL modem to keep connected to the web, and my two Vonage boxes for VOIP phones, for about 15-minutes — enough time for graceful shutdown. There are protected and non-protected outlets on it. If you have an inkjet printer that would work on it, too, but NOT a laser printer (too much “juice” needed). We don’t get much lightning in my area (SF East Bay), but occasionally it happens. We do lose power in my neighborhood way too often. It is so cool to have all the lights in the room go out, but the PC never even flickers… Last time that I had to replace my garage door opener, I even got one with a UPS that lasts for up to a dozen up-down cycles.

As far as backups, I use more than one internal removable rack drives, 2 TB, which have more than enough space for native file (copy) of all my data, plus image backups of the attached PC plus several other systems. I swap them out regularly and back up the backup to another separate 2 TB removable drive on a different PC that is rarely turned on, so I feel pretty safe.

Works for me. Hope that provides some food for thought. Best wishes.

Rob

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maybe

try it !!

get a surge suppressor and a ups with surge suppression
use both in series

best to have two HD usb drives that you alternate
only plug one in at a time

also stops virus from contaminating both at once

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get a surge suppressor and a ups with surge suppression
use both in series

IIRC, there’s some reason for NOT running them in series, but I can’t remember why (even if I did know at one time).

Zig

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Zig, All,

You should never plug a UPS into a surge suppressor (wall – UPS – Surge). However, it is ok to plug a surge suppressor into a UPS. (wall-UPS-Surge) At least that is my understanding of the situation and currently how I have mine setup. HTH :cheers:

May the Forces of good computing be with you!

RG

PowerShell & VBA Rule!
Computer Specs

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RG,

I believe your first example should be (wall – surge – UPS).

Zig

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Sometimes, the USB device with power adapter (or wall wart) could fry the laptop/PC, rather than the other way around.
It happens more frequently than the reverse.
USB device with its own power adapter could be quite damaging to the rest of the system, especially if a laptop is powered off.
Use a USB hub in the middle.
The hub helps to isolate. And if something happens, the hub burns first as sacrificial lamb.
Technical reason:
USB cable includes 5V and ground wires. The other pair is data wires. The 5V wire could be directly connected to the PC’s 5V line. That is, the 5V on USB device is connected to the 5V of your PC power supply! Some USB devices have mechanism or IC/fuse to do the separation. Some *DON’T*. (You don’t know unless you open and study it. Brand name has some guarantee but not always.)

I propose make it a habit to only plug into a hub than directly to a laptop/PC.

Laptop, with less muscular power supply, is more vulnerable. Even Apple laptops.
Hint: if the laptop/PC cannot boot normally, unplug all USB devices, especially those with its own wall wart or power supply. Then thank God your PC/laptop is not burned.

Re surge suppressor:
Surge suppressor, basically, is a fast acting high voltage Zener Diode (aka Voltage limiter). (I skip the details here.)
Say, at 400V, it caps. So a 1000V spike is limited to 400V. Damage is measured in energy. In turn, it is measured in time duration of the spike. Most spikes, though high voltage, is only nano-seconds long and quickly decay, hence ‘low’ energy. The ‘voltage limiter’ can handle it.
The basic not so good characteristic of surge suppressor is its high capacitance. The capacitance may short out high radio frequencies in the AC line.
Depending on application, it could be good (suppressing noise). For Ethernet over Powerline, or radio frequency control using AC line, it is a nightmare, no less.

With this understanding, plug anything before, after, in between, suppressor(s), should have no consequence. (Unless of course, your PC, or your UPS, is constantly outputting 400V or higher AC voltage!)

As for surge suppressor in series:
Someone already mentions: No good. Worse, actually… but not as bad.
Tech:
As mentioned, suppressor device is to create a short between 2 wires.
The nano-second spike could create as much as 10 Amps or higher.
Worse still, at nano-second rise time, it is effectively very high frequencies.
Skin effect is in full force. All this high current only rides on surface area of the wire, making the wire a lot more resistant.
Bad enough? Now that is not as bad as this: Wire inductance.

All wire, even an inch long straight wire, has inductance. At very high frequency, its inductance is high enough to almost block the high frequency current.
Now imagine a 6-foot power strip connected to another 6-foot power strip. When the 2nd power strip suppressor limits, the current now has to pass through its own 6-foot ‘inductor’, then to ANOTHER 6-foot ‘inductor’. Effectively, the wires ‘float’ way above ground level. Or, bad protection.
The most effective suppressor protection is a wall plug, directly plug into the wall outlet, not a power strip with 3 or 6 feet tail. That is, when the ‘voltage limiter’ shorts the two wires, it sees only the AC outlet terminals.

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My daughter’s power supply died in a flash taking the video card, and both system HDD and backup HDD with it.

Nothing in these symptoms even suggest it was an external surge. These are classic symptoms of a power supply that was missing essential functions. These defective supplies are often sold to computer assemblers who have no electrical knowledge.

A destructive voltage created by a supply that is missing essential functions would be incoming to every PC components – including USB connected devices.

Those same functions also define protection inside the power supply that is superior to any power strip or UPS protection. Unfortunatey, too many recommend power supplies without citing the always important numbers and because they do not even know what numbers are important. That damage is classic of a computer’s power supply that was defective when purchased.

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Westom, Thank you for your input. It was an Antec sp500 power supply but had been in service for several years. It was plugged in to a Belkin UPS, also several years old. I replaced the battery once. She lives in an older home, built circa 1950, without updated wiring. I have not had a recent look at the setup as I live 200 miles away. I assembled three computers using the MSI K9N6SGM mother board. My daughter’s, my wife’s (no problems yet), and mine that I had to re-cap two years ago. My daughter’s machine was running Vista, my wife is running Win7 and I am running Win8.1 with an SSD. I am tempted to upgrade but these are adequate for Spider, Freecell, Facebook and Skype. Thanks again to all.
RWC

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It was an Antec sp500 power supply but had been in service for several years. It was plugged in to a Belkin UPS, also several years old.

Neither age nor manufacturer nor software adds anything to better explain the damage. A supply must define, in specification numbers, functions that make that damage impossible. Functions that are specifically required by ATX Standards. Your damage is classic of a supply missing essential functions. Power supply manufacturer is not responsible for providing those function. A computer assembler is responsible for selecting supplies that meet those standards. Therefore some power supplies do not always meet those standards – are missing essential functions.

Nothing on its power cord (ie UPS) is relevant. Even 1930 two wire AC circuits should not cause hardware damage. In fact, a UPS in battery backup mode is typically some of the ‘dirtiest’ power a computer will see. Due to other functions that must exist in every supply, even a dirtiest UPS is sufficient power for a computer. Those functions are irrelevant to what would explain that hardware damage.

Another way of causing that damage is to disconnect parts when a computer is off but still connected to AC mains. Reasons why should be obvious.

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Neither age nor manufacturer nor software adds anything to better explain the damage.

Not true. Specs are one thing, but only when the components continue to meet them. I spent many years debugging hardware faults to component, internal gate and ultimate cause of failures. And I have been present at the often explosive end of many power supplies. Power supplies are full of capacitors and all have some sort of transformer or other coil in them. Capacitors are made in many different ways, but nearly all of them age and there are many failure modes. Since they store charges, they can unleash quite a bit of energy when they fail. And since they frequently are used to slow voltage transitions and in circuitry which limits voltage swings, a failed capacitor can allow high voltages to pass into other parts of the supply and even out into the equipment. Copper windings are covered in a thin layer of varnish as their only insulation. Coil wire insulation is much better than it used to be, but only due to improved quality control, not to any basic change in how a coil is constructed. Heating/cooling can cause cracks in the varnish allowing shorts to form. Age can dry the varnish making the cracks more likely. Shorts reduce transformer output voltage causing the downstream components to draw more current which exacerbates the problem. Same with flyback coils. Etc., etc.

Component engineers constantly strive to improve the reliability of their components, but cost is always an issue (just compare the price of a commercial grade cap and a military grade one) and so consumer grade equipment does not have the most reliable components. Sorry, it just doesn’t.

And we all make many other choices based on cost. There is always something more we could do if we were willing to spend more time and money. In a sense, we are all engineers of our own little worlds. (That’s what an engineer spends most of his time doing, trading off function for cost.)

I personally like the idea of using an external USB case with a replaceable drive with its own power supply. If the external drive is taking its power from the host computer, then host power supply problems will affect it directly and could damage the drive. If the external drive is not taking its power from the host computer, then a catastrophic PS failure in the host computer could damage the USB transceivers in the external drive, but then you could move the disk to a new external drive housing and it will probably still work fine. If the external drive PS fails catastrophically it could take out the USB transceivers in your PC, but probably would not damage the data on the internal drives. If your MB has multiple USB controllers on it, you might not even have to replace it, though you might have one or more USB ports that no longer work. And if you were really concerned about protecting the PC you could use an add-on USB controller for your external drive. That way damage from the external drive would probably be limited to the replaceable USB controller.

But these are all just probabilities. Such is life. This proposal only protects from one failure mode which you probably won’t see again. The next time it will be something different. Other suggestions have been made which will improve your data security even more. Distributing your backups, for example. Backing up to the “cloud” sounds attractive, but I don’t have the network bandwidth to fully backup even my personal PC, much less my other six business computers. I backup only my most important corporate data to an offsite computer. The rest I distribute around to other computers on my LAN. Your situation might be such that you can backup everything to offsite storage. Or you can do local backups to a USB drive and then unplug it. That’s too much for my old brain to remember, but it obviously works for some. We’re all different. I’m sure you can find something that works for you in all of these postings. It’s a great group here in the lounge.

Good luck. I hope the data on your drive is recoverable. It might be, you know. Try it in a different PC (or install it in an external USB housing, just in case…) And there are data recovery services if that doesn’t work. I have used one once and they saved my bacon.

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