WD External hard disk failure...

It is not good news, I suspect.

Looking at the back of the enclosure, it uses 12VDC. That same

12VDC _could_ be connected directly to the controller board (current for the motor) on the disk drive, as well as powering a converter to make the necessary +5V to power the rest of it. That means both the bridge board in the enclosure and the drive itself could be damaged.

When placing an Adaptaplug in an appliance, a smart engineer would place a diode, to prevent accidental polarity reversal. This kind of plug is really a brain-dead solution, and should have stayed at Radio Shack. The plug would be fine if it carried raw AC, but polarized DC is just stupid. Any connector with a keying mechanism that prevents reversal would be better than that. Adaptaplugs tend to make flaky contact after years of use, and would not be my first choice as a solution. I have enclosures here that have a four pin connector (+5, +12, GND, GND), and it can only be plugged one way. That would have been a superior solution.

Try option (3) from your list first, and see if there is any response from the drive. If the drive still works, then you can consider (1) or (2).

Paul

Yup, sure sounds like he blew it up. Don't do that...

Those are pretty much your options, other than sending it back to WD for service. Even if it is under warranty, and you didn't void the warranty by usingthe wrong power adapter connected with the reverse polarity, and they do "fix" it, your data will be gone.

I'd open it up and look for blown-up stuff (traces, components, fuses) and then one of the above.

Ill try that suggestion Paul! I hope option 3 works :(

And from no on, Im going to build it myself, get a HDD and build an enclosure for it!!

Keep your brother under control.

Q

I'd have to disagree here, a diode is a GREAT idea, far superior to a polarized plug. With the polarized plug one is forced to use only the mating socket, limiting power sources, and limiting viability of the support for reuse some day.

These special plugs and sockets may easily cost more as well, more than adding a diode which is a trivial cost.

So what if the diode drops a few tenths of a volt? "Easy" and "Cheap" are not always brain-dead, it's worked well for years and would've this time too. This might be more of an issue on very low voltage portable battery-powered devices.

Another protective method is to install a reverse-biased diode between the power rail/wire and ground, and place a fuse between the power jack and the board. When power is hooked up correctly, there's no voltage drop and no loss of power in the diode. If power is hooked up in reverse polarity, the diode conducts (hard!) and the fuse blows immediately, limiting the amount of reverse voltage applied to the circuit to a volt or so for a small number of milliseconds.

The original poster might check to see if this is what happened to his drive (I infer that his drive is a standard parallel-ATA with an outboard USB 2.0 adapter-thingie on it?). There might be a blown surface-mount fuse, near the power-cable connection point on the adapter. If so, simply replacing this fuse might get the adapter and drive working again.

I tend to prefer to use self-resetting polymer "fuses" in this sort of application - nothing to replace if the fuse "blows" due to a reverse polarity event - but they're more expensive than standard fusible types.

--
Dave Platt                                    AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
  I do _not_ wish to receive unsolicited commercial email, and I will
     boycott any company which has the gall to send me such ads!

Another thought would be to try plugging it into a different USB port. If you have another working USB device try swapping the drive's USB port with the other device.

The chances are more that the external drive enclosure's USB/IDE interface blew but it's worth a try.

I don't know if I made myself clear enough or not.

I'm referring to the fact that many companies use the circular two contact plugs, and some of them make the center pin (+) and some make the center pin (-). That is a recipe for disaster if the appliance is not protected with a diode, as the consumer can mate any wall wart that even remotely resembles the right one.

If you go to Radio Shack, there are about 15 different kinds of Adaptaplugs. At least a couple of them will fit in holes they really shouldn't, which means the size of the plug, doesn't provide a means of preventing the wrong things being plugged together. And if I want, I can connect a 12V supply from one product, into the 7V socket on another product.

On the "Radio Shack end" of the stuff they sell, there are two styles of pins. Some Adaptaplugs have asymmetric pins, which prevents installing a Radio Shack adapter on one of their power bricks the wrong way. Other kits from Radio Shack have symmetric pins, which causes the center conductor of the Adaptaplug to be either (+) or (-) without the customer knowing. In fact, for some of this style of product I own, I use my multimeter to verify the center pin is the right polarity, before each and every use of the product.

Such a connector concept is "for the birds". Each voltage should have its own connector style. Each connector should be designed so it cannot be reversed. A requirement like that would prevent the proliferation of 15 very similar connectors/sockets, and then perhaps personal electronics would have fewer operating voltages.

This is the right way to build a disk enclosure. No mistakes here. No brick. Just an AC power cord.

This is the second best concept. It uses an external brick, but the power plug is "DIN-like" and the pattern unique enough that there is only one way to connect it. I have seen a similar molded 1x4 style plug as well, for disk enclosures.

This, on the other hand, is the height of absurdity. This is fine for hackers, or home rocket-scientists, but for people who want their stuff to "just work", what were they thinking ?

Paul

Krazy (or hot-melt) glue is your friend for this kind of application, if you don't mind dedicating your Adapta power supply to that particular application.

And yeah, there oughta be a standard, but there isn't, which is why I label all the wall-warts with the device they belong with...

Ah, now I see. Yes that's certainly a problem... think RS just went for the lazy generic approach.

I have a few old SCSI boxes like this, retrofitted one for USB2 and while it's definitely built like a tank, it's too large for most people's taste, and such a design for a new product is probably too expensive to be very competitive in the consumer market.

Yes. This is 'historic'. Basically, US, and UK kit will tend to use tip

+ve, but stuff from Japan, uses tip -ve. Even here there are exceptions with companies electing to 'buck the trend'.

There has been a system offering this for some years. There is a 'standard' family of connectors, very like the round wall-wart power plug, except the centre pin is the other way round. This comes in four or five different sizes, and the standard specifies what voltage is associated with each plug size. Some kit in recent years (especially things like mobile phones), have started using this design. However 90% of kit still uses the old style tubular plug, because it is so cheap, and so readily available...

Also the cost to make the supply work, and be approved 'worldwide' is prohibitive. The advantage of the wall-wart approach, is that from the point of view of the company making the kit, it does not have to be approved as a 'mains' appliance.

Best Wishes

Tip?

Typical DC coaxial connector in US has always used center positive and sleeve ground. This includes products made in Japan. There have been some ill-conceived products using reverse polarity but never enough to be anything other than a rare annoyance.

Many of those are used in space-constrained designs, not quite what's being faced on the external storage boxes, where I'd tend to think the durability of a larger connector is better. Voltage - keying mind be a reasonable approach when a device does have a specific input requirement but many devices today regulate down the voltage further so the keying is in itself a potential problem if one loses the power supply or it fails, making it possibly much more expensive to replace. For example, right now my cable modem would run off of any of more than a dozen spare wall-warts I have lying around, because it uses a standard connector ... but it also has a diode in series on the power so a reversed polarity connection wouldn't be problematic.

I'm not entirely sure about that, generally such devices are engineered to the highest common denominator - IE, to pass in any country they might be sold in. This only for approval, for the voltage differences I suppose in some cases it might be cheaper to produce different supply rather than one full-range supply.

This may be the biggest advantage, though I also tend to think it's cheaper due to the commodity status of a common wall-wart, even switchers these days, rather than having to spec and buy or build custom supplies.

Well, in my case too, the center was positive and the wrap around was negative. Actually it wasw my bad to get this, after i lost the OEM adapter, I didnt want to spend $25 to get an adapter that just works for my External drive and now I'm repenting for it. Its my wal-mart mentality bang for the buck kinda thingy that went wrong.

It does have a fuse right after the power supply get in to the board, but I'm not sure whether its blown or not, I alreayd opened the cover but I dint have the instruments to check the voltage.

Another thing is, the lights are lit when I plug in the power source, that makes me think that the fuse is fine.

But anyway, ill remove the drive (its a standard WD Caviar IDE drive) and hook it up to a PC.

Incase that does not work out good, any alternative methods to recover the data? As I searched in the news group I see professionals charging $100 per gig. :(((

I did try it in different machines, the USB recognizes it as a mass storage device. But I'm getting a code 10, which means the device cannot be started.

You didn't need to spend $25, only to get one that was suitable. For example, you take the output labeling on the original and find a close match (if not exactly same) voltage and at least as much amperage. If it is a simple unregulated transformer type wall-wart rather than a switching type, do not overshoot much on the amperage unless you're sure the device regulates down the supply further since a lightly loaded simple-transformer will have a higher voltage in such uses.

So for example if an original supply had 12V and 800mA output, seeking another 12V 750-1000mA rated supply (considering switching vs unregulated as mentioned above) with the same common polarity and barrel connector would work- and can generally be found for anywhere from $1 to $10 online, a bit more for those outputting multiple voltages. If none with a suitable connector can be found, one might get a connector from Radio Shack or online separately- though too many separate online purchases and you're close enough to the $25 mark again as the individual shipping charges start to add up.

I would be hesitant to buy same adapter you already had fail, since the failure is an indication this specific make/model may be prone to problems for whatever reason.

Without a multimeter and a bit of troubleshooting skill, you are left to swap parts around, trying the drive in another system an another drive on that system.

If it is a fuse on the input, for the entire device, yes it would clearly indicate the fuse is not blown. I don't know exactly what yours is like though, nor see what you do- there are other various reasons for fuses, like a fused connection if it has a hub and USB port(s) integral.

If the drive is damaged it's most likely the circuit board, in which case you could try to source another identical board and swap them... though I don't know details about that model of drive, just how similar any two models have to be to find a compatible board, nor which /what PCB markings to use to find this.

Otherwise, if the drive won't work you have no options left except the recovery service, or "maybe" trying to reverse engineer the PCB/components and find the specific fault, if it were only one thing faulty. I glanced at a different drive here (maxtor 80GB) and it had a protection diode on the power intake, AFAICT, I didn't look really carefully onlly long enough to see the diode since it wasn't same model and wouldn't be diretly applicable.

I would suspect at least the USB board in the enclosure is fried, but no guess about the drive itself.

A third way to use a diode which is also lossless is to interrupt the supply wires inside the equipment with a the contacts of a relay and drive the relay coil from the upstream side via a series diode arranged in forward conduction polarity from a correctly applied supply voltage. If that supply is reverse polarity, the diode doesn't conduct and the relay won't close so the equipmemt is protected.

HTH

--
Graham W   http://www.gcw.org.uk/ PGM-FI page updated, Graphics Tutorial
WIMBORNE   http://www.wessex-astro-society.freeserve.co.uk/ Wessex
Dorset UK  Astro Society's Web pages, Info, Meeting Dates, Sites & Maps
Change 'news' to 'sewn' in my Reply address to avoid my spam filter.

In another case somebody suggested getting an identical drive, (as you did not mechanically damage the drive),and use its electronic board to try and readout this drive.Might not work, as the head amplifiers could be inside, but it is less expensive then the data recovery service.(even if it costs you a new drive).

That would work too, though I tend to believe the most predominant issue in these low-cost inclosures is the cost to implement any kind of protection, I doubt the budget would accomodate any decent relay, especially if they were cost constrained so much that they didn't even add a low dropout diode alone. We can't even necessarily consider the diode a "loss" per se, because if the supply is kept at constant voltage and downstream is lower, the downstream parts can tend to use less power at this lower voltage... or crash if the voltage is TOO low, but given something like a schottky you'd be looking at about 2% voltage drop on 12V or higher supply which shouldn't be a problem.

I got a multimeter from work today...checked all the voltages and currents, its all perfect, uptill the point where it goes to the HDD :(

I cannot switch boards as I heard that WD drives have some information specific for each drive embedded in those boards, dont know how far its true, but i dont want to ruin my changes of recovering the data.

Ill try mounting this drive thro IDE on a PC and let know how it goes...