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4TB external HD
On Wed, 27 Jun 2018 21:48:33 +0100, Brian Gregory
wrote: On 26/06/2018 23:25, Paul wrote: Brian Gregory wrote: On 26/06/2018 03:20, Paul wrote: Brian Gregory wrote: On 25/06/2018 23:44, Paul wrote: Brian Gregory wrote: On 25/06/2018 22:01, Ed Cryer wrote: Ed Cryer wrote: Paul wrote: Stephen Wolstenholme wrote: On Mon, 25 Jun 2018 12:53:03 +0100, Ed Cryer wrote: I have a Seagate 4TB external HD, powered, like this; https://goo.gl/q1z7RC It works fine with Win7. No sign of trouble. But when I plug it into Win10 the system dies. Strangely, when I boot with it plugged in, everything goes fine. There's nothing relative in the Windows Log, other than info that the system didn't shut down properly before the reboot. Has anybody seen this? Or, any hunches as to what's causing it? Ed I had a similar problem with a Verbatim drive. It was fixed by a new driver that was applied by an automatic update. I assume Seagate have some driver fixes. Steve It should be using a regular USB Mass Storage driver. The drive is 3.5" and has an external 12V @ 1.5A adapter. The question would be, where does the +5V come from. A lot of drive enclosures, convert some of the 12V to 5V to run the logic board on the hard drive. So rather than the wall adapter having four wires like a Molex, only +12V comes from the adapter, and the +5V is produced on site. (Wall +12V ------------ Adapter ---- +12V ------ Hard drive motor * Wart) GND ------------ Board** ---- GND* ------ ******************************** ---- GND* ------ ******************************** ---- +5V* ------ Hard drive logic board (not all pins shown) ***** +5VSB ------------ USB to****** TX+ ------ Hard drive ****** D+*************** SATA******** TX- ------ data ****** D-*************** Converter*** RX+ ------ connector ****** GND ------------- Chip******** RX- ------ 7 pin (3 GND) The USB cable by comparison, has a source of +5VSB at up to 900mA on USB3. If the ATX power supply doesn't have sufficient +5VSB rating, and you actually overload +5VSB, it can cause the motherboard to shut off. Instead of doing a restart, it would appear to spontaneously shut off. Maybe they made it like this, but... unlikely. ***** +12V ------------ Adapter ---- +12V ------ Hard drive motor ****** GND ------------ Board** ---- GND* ------ ******************************* ---- GND* ------ ******************** +-------------- +5V* ------ Hard drive logic board ******************** | ***** +5VSB ---------+-- USB******** TX+ ------ Hard drive ****** D+*************** SATA******* TX- ------ data ****** D-*************** Converter** RX+ ------ connector ****** GND ------------- Chip******* RX- ------ 7 pin (3 GND) But even though that looks bad, it's not possible to tell from the outside, exactly how the external storage box was designed. If it was a driver issue, you'd expect to see some error info in the Reliability Monitor related to the driver. The drive might not be spinning when it is plugged in during a session, but spinup current comes from the 12V 1.5A adapter, rather than the USB bus cable. The USB bus cable should only power the adapter board inside the enclosure. Or in a more exotic design, the bus power could also be used to run the hard drive logic board. For a driver issue, you'd expect to see a BSOD on the screen for a short time. If you disabled automatic restart, then the BSOD would stay on the screen longer. If it really is a power issue (crushing of +5VSB) then changing the automatic restart setting would not change the symptoms. If the computer shuts off and doesn't restart, that sounds more like a +5VSB issue. And while placing a USB3 powered hub between the computer box and the external drive would sound like fun, those aren't always designed properly either. Sometimes there are undesired interactions between the downstream +5V on the powered hub, versus the +5VSB on the host side of the hub box (the "backfeed" problem). If an iPad was being charged off the PC, at the same time the HDD enclosure had the USB data cable plugged in, that would represent a pretty heavy load on +5VSB (several amps). *** Paul Hi Paul. I've just tried it on another Win10 box and it works perfectly there. I took it back to the faulting box, booted with it in, uninstalled it, rebooted ...... problem still there. I've not had any other USB problem with the box. I've plugged in other HDs, memory sticks, external bluray writer. All fine. Ed The main difference that leaps out at me is that the 4TB drive has a power adaptor; none of the other devices do. Ed My theory: The power supply on the drive is cheap Chinese rubbish and has no earthing and measurable mains voltage leakage and the PC shuts down when a small spark jumps from the USB cable to the PC as you insert the USB connector. If the drive's power supply is earthed through to it's output then maybe the PC isn't earthed or an earth loops is causing current flow that crashes the PC. I would be alarmed if I saw sparks fly between the PC USB connector and a powered USB 3.5" drive. The ground shell touches first, and we'd be talking about a spark-into-ground event, with the possibility of crosstalk between the shield and internal conductors to upset other electronics. This tends to be worse on *front* panel connectors. Due to the front connectors never being earthed properly (typically set in plastic, and only the shield on the cable provides ground). The back connectors have obvious physical paths to chassis, and a slightly lesser chance of induced upset. The wall adapter has 230V on one side. The HiPot test is supposed to verify 1100V withstanding for some period of seconds. But the sticker or proof of test might not be visible from the outside. ATX supplies sometimes have a visual indication on them that they've been HiPot tested. It's best to apply the test after final assembly, as if anyone makes a dopey mistake, the test might catch it. The transformer(s) themselves could be HiPot tested, and that's probably done on the transformer manufacturing line. But that's not likely to be the last test. You want a final test, to verify no creepage & clearance problems, or solder splashes where they don't belong. Visual inspection (even robotic) isn't enough for safety purposes. If someone files a law suit against you, you can show the HiPot stamp on the unit, show the court your test station for the procedure and so on. For whatever that's worth. If you do see a spark, well, stop using it :-) If the design is intended to float, it should not throw sparks. And there's no reason for that test case to violate the HiPot max. If you raised the PC chassis thousands of volts above the rest of the house, yes, you'll see a spark on the resulting multiple HiPot failures. *** Paul I said small spark. I've seen this happen on an HP printer. A Deskjet 720 if I remember correctly. Luckily I could leave it connect all the time so it wouldn't crash the PC. I still don't see you properly describing exactly what happens, a crash or a power off or what. If you short +5VSB to ground, you get a power off. Never heard of crowbar protection? I have. I designed it into a power supply at home, at the age of 18. I don't think that's what you mean though. You probably want OCP (Over Current Protection), which can be implemented thermally (regulator overheats at a certain current flow level and removes output). There is also foldback current protection, where the device reduces current flow, protecting both the load and the supply. There is also "put-put" mode, which early PCs used, leading to more successful boots, even if a PC "wasn't feeling well". That mode is suited to the older computers running 30-35W loads or so for the processor. There are several approaches to overload. ******* Crowbar is for OVP. OverVoltage Protection. What it seeks to do, is clamp the output to zero volts, causing the OCP to cut in. Crowbar was intended for cases where the failure modes of the power supply, made it really easy for the supply to be in a permanent "high voltage output" state. For example, a series pass linear which is jammed in an "ON" state, would leave the DC output permanently too high. In some cases, a supply with a fast-blow fuse located elsewhere in the circuit, application of the crowbar would blow the fuse. Modern SMPS attempt to remove switching drive from the primary side, on a fault. So there's no need to crowbar them. As soon as the switching action stops on the primary (even if one transistor is permanently jammed on), it takes alternation to pass an AC signal through the isolation transformer to the secondary. DC to DC converters (like the secondary power board in 80+ supplies), have different fault modes than the main 12V section, and may require a different approach. (They could be buck regulators for example, as they don't need isolation as a feature.) While some of the chips used may remove primary drive to the buck transistor (causing MOSFET to go to OFF state), that's not sufficient to handle all fault scenarios. It would be an unusual design today that uses a crowbar. There are plenty of options in modern supplies. For example, if the secondary board in an 80+ fails, you can kill the switching action on the primary side of the main transformer, or you can disable the PFC front end (the part that power-factor-corrects the AC load caused by the ATX supply). The advantage of killing the switching action, is protection is closer to instantaneous. Killing at the PFC requires 16mS to a second or so before the output stops. ** Paul So YES a pulse getting on a power rail can cause a power supply to cut out. I have a Clamp Leaker 140. |
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