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Electronics Repair (sci.electronics.repair) Discussion of repairing electronic equipment. Topics include requests for assistance, where to obtain servicing information and parts, techniques for diagnosis and repair, and annecdotes about success, failures and problems. |
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#1
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Help! I've burned up 3 SATA drives today
I got a used computer on Saturday at a yard sale. I bought it for the case, although it came with a motherboard and power supply but no drives or video card. I put a video card into the machine, along with an IDE drive and the system ran fine. I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I swapped out the power supply for a second unit, and put in another SATA drive. I checked voltage to the molex and it was 11.86 volts and 5.09 volts. It happened again, when I turned on the power I killed the second SATA drive. I took my motherboard out of the new case and put it back in the my old case. Everything runs fine. I put another power supply in the "new" case, this power supply did have SATA power cables. Back into the case went my motherboard. Again, upon power up a third SATA drive was blown. The SATA cables coming from the power supply had an extra orange wire that the molex adapter cables do not have. Three SATA drives down the drain. IDE drives work fine. The last drive that burned up had only the SATA power cable connected. That means the motherboard is out of the picture. I have run out of expendable SATA drives. Any idea of what might be the problem? |
#2
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Help! I've burned up 3 SATA drives today
En el artículo , root
escribió: I have run out of expendable SATA drives. Any idea of what might be the problem? If the drives had both Molex and SATA power connectors - not all do - and you were connecting both (you don't say), that would damage it. Connect either the Molex or the SATA but never both. I would have said you might have a mis-wired Molex-to-SATA adapter (it's not unknown, especially with cheap crap coming out of China), but you ruled that out by using the PSU's own SATA connector. -- (\_/) (='.'=) (")_(") |
#3
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Help! I've burned up 3 SATA drives today
Mike Tomlinson wrote:
En el artículo , root escribió: I have run out of expendable SATA drives. Any idea of what might be the problem? If the drives had both Molex and SATA power connectors - not all do - and you were connecting both (you don't say), that would damage it. Connect either the Molex or the SATA but never both. I would have said you might have a mis-wired Molex-to-SATA adapter (it's not unknown, especially with cheap crap coming out of China), but you ruled that out by using the PSU's own SATA connector. Thanks for responding. A long time ago I had a SATA drive with both power connectors. None of the drives I ruined were the dual power socket types. I have a lot of the Chinese adapter cables, and the ones I used were from China: Deal Extreme. I have put a brand new ThermalTake power supply in. I have to wait until I can round up some old SATA drives for testing. |
#4
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Help! I've burned up 3 SATA drives today
En el artículo , root
escribió: Thanks for responding. A long time ago I had a SATA drive with both power connectors. None of the drives I ruined were the dual power socket types. OK, so that rules that out. Worth mentioning though. I have a lot of the Chinese adapter cables, and the ones I used were from China: Deal Extreme. I've bought stuff from them via ebay and have been happy. I have put a brand new ThermalTake power supply in. I have to wait until I can round up some old SATA drives for testing. I can't imagine what the problem might be, but hope you don't blow up any more drives ;o) There's some knowledgeable people on news://comp.sys.ibm.pc.hardware.storage Suggest you post there. Beware of the group troll, Rod Speed. Best killfiled. -- (\_/) (='.'=) (")_(") |
#5
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Help! I've burned up 3 SATA drives today
On 14/02/2012 01:36, root wrote:
The last drive that burned up had only the SATA power cable connected. That means the motherboard is out of the picture. I have run out of expendable SATA drives. Any idea of what might be the problem? So, the motherboard works in another case but causes problems if installed in this one? When you checked the voltages with the data lead disconnected, was the motherboard still connected/powered? Pure conjecture of course, but maybe there is a partial short causing an odd voltage issue at the sata connector, sata drives in general do seem to be more prone/sensitive to power issues than ide ones. |
#6
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Help! I've burned up 3 SATA drives today
Mike Tomlinson wrote:
Beware of the group troll, Rod Speed. Best killfiled. Did that years ago. |
#7
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Help! I've burned up 3 SATA drives today
Lee wrote:
On 14/02/2012 01:36, root wrote: The last drive that burned up had only the SATA power cable connected. That means the motherboard is out of the picture. I have run out of expendable SATA drives. Any idea of what might be the problem? So, the motherboard works in another case but causes problems if installed in this one? When you checked the voltages with the data lead disconnected, was the motherboard still connected/powered? Yes, when I checked voltages at the molex connector the motherboard was still powered up and running. Pure conjecture of course, but maybe there is a partial short causing an odd voltage issue at the sata connector, sata drives in general do seem to be more prone/sensitive to power issues than ide ones. |
#8
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Help! I've burned up 3 SATA drives today
Big advance since my last post. I scrounged up
another expendable SATA drive and powered up the system with the new ThermalTake PS. All went well. That gave me the courage to put in two more SATA drives and the system is running now with all three drives in. No progress in resolving the 3 burned drives but my immediate goal of bringing up the system in the new case is near complete. All this, BTW, was because of the case: it is a D-Vine Home theater case. Something suitable for putting in a living room home entertainment system. |
#9
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Help! I've burned up 3 SATA drives today
In article , root
writes Did that years ago. ) You and a thousand others, I suspect. -- (\__/) (='.'=) (")_(") |
#10
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Help! I've burned up 3 SATA drives today
In article , root
writes Big advance since my last post. I scrounged up another expendable SATA drive and powered up the system with the new ThermalTake PS. this is the one with the included SATA power plugs? Perhaps you should check the Molex-to-SATA power adapters you were using previously. It isn't unknown for that sort of thing to arrive incorrectly wired. Quality checks - they've heard of 'em. -- (\__/) (='.'=) (")_(") |
#11
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Help! I've burned up 3 SATA drives today
Mike Tomlinson wrote:
In article , root writes Big advance since my last post. I scrounged up another expendable SATA drive and powered up the system with the new ThermalTake PS. this is the one with the included SATA power plugs? Yes, this PS has the SATA power plugs. Perhaps you should check the Molex-to-SATA power adapters you were using previously. It isn't unknown for that sort of thing to arrive incorrectly wired. Quality checks - they've heard of 'em. Before closing up the new system, I tried the Chinese molex-SATA cables and they were OK. I intend to pursue an explanation of what happened. If I find out I will post here. Thanks for the suggestions. |
#12
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Help! I've burned up 3 SATA drives today
root Inscribed thus:
I got a used computer on Saturday at a yard sale. I bought it for the case, although it came with a motherboard and power supply but no drives or video card. I put a video card into the machine, along with an IDE drive and the system ran fine. I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I swapped out the power supply for a second unit, and put in another SATA drive. I checked voltage to the molex and it was 11.86 volts and 5.09 volts. It happened again, when I turned on the power I killed the second SATA drive. I took my motherboard out of the new case and put it back in the my old case. Everything runs fine. I put another power supply in the "new" case, this power supply did have SATA power cables. Back into the case went my motherboard. Again, upon power up a third SATA drive was blown. The SATA cables coming from the power supply had an extra orange wire that the molex adapter cables do not have. Three SATA drives down the drain. IDE drives work fine. The last drive that burned up had only the SATA power cable connected. That means the motherboard is out of the picture. I have run out of expendable SATA drives. Any idea of what might be the problem? Possibly open circuit grounds on the power connector... -- Best Regards: Baron. |
#13
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Help! I've burned up 3 SATA drives today
root Inscribed thus:
Mike Tomlinson wrote: In article , root writes Big advance since my last post. I scrounged up another expendable SATA drive and powered up the system with the new ThermalTake PS. this is the one with the included SATA power plugs? Yes, this PS has the SATA power plugs. Perhaps you should check the Molex-to-SATA power adapters you were using previously. It isn't unknown for that sort of thing to arrive incorrectly wired. Quality checks - they've heard of 'em. Before closing up the new system, I tried the Chinese molex-SATA cables and they were OK. In that case please ignore my last post. Thanks. I intend to pursue an explanation of what happened. If I find out I will post here. Thanks for the suggestions. -- Best Regards: Baron. |
#14
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Help! I've burned up 3 SATA drives today
Baron wrote:
root Inscribed thus: I got a used computer on Saturday at a yard sale. I bought it for the case, although it came with a motherboard and power supply but no drives or video card. I put a video card into the machine, along with an IDE drive and the system ran fine. I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I swapped out the power supply for a second unit, and put in another SATA drive. I checked voltage to the molex and it was 11.86 volts and 5.09 volts. It happened again, when I turned on the power I killed the second SATA drive. I took my motherboard out of the new case and put it back in the my old case. Everything runs fine. I put another power supply in the "new" case, this power supply did have SATA power cables. Back into the case went my motherboard. Again, upon power up a third SATA drive was blown. The SATA cables coming from the power supply had an extra orange wire that the molex adapter cables do not have. Three SATA drives down the drain. IDE drives work fine. The last drive that burned up had only the SATA power cable connected. That means the motherboard is out of the picture. I have run out of expendable SATA drives. Any idea of what might be the problem? Possibly open circuit grounds on the power connector... Using my last expendable SATA drive, I retraced my steps as closely as I could remember what I did on Saturday. Starting with the original MB that was in my new case, I put back the original power supply, and plugged in the SATA drive. No Problem. I used the same Chinese SATA adapter cables as I did. I have no idea of what the problem might have been since it is not reproducible. It might be that, in my haste, I didn't push the SATA power plug all the way in and it might have been askew. This is really a stretch because I have pushed on SATA cables for a long time, and I would have had to repeat that screw up two more times. |
#15
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Help! I've burned up 3 SATA drives today
En el artículo , root
escribió: I intend to pursue an explanation of what happened. If I find out I will post here. Thanks. Would be very interesting to know what it was. -- (\_/) (='.'=) (")_(") |
#16
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Help! I've burned up 3 SATA drives today
Having read this, it seems that most "normal" possibilities have been
eliminated. It's not known though if you are mounting the drives or letting them hang around, but if you are actually mounting them in the case you might actually have a ground fault. Now nothing has changed inside the case and the problem is gone, but what about outside the case ? Grounds can be funny things at times. What's more, there may have been some sort of ground fault that eventually got blown out. The problem with that theory is that a ground fault would almost for sure be in the PS, at least in an ATX case right ? I mean the wires to the power switch are not on the hot side. I have seen some strange ground fault problems. Try to think back, if the drives were not mounted, were they in electrical contact with the case ? And of course don't forget what might have been plugged in. Hell under certain conditions a ground fault in the monitor might cause something like this. Not to coin a phrase LOL - but think outside the box. I think that somewhere down the line you might wind up blowing another one. What would be interesting to know is if there are any significant differences in the architecture of the power distributoin between IDE and SATA drives. How many grounds and where ? Whenever a problem seems to cure itself I get butterflies in the ulcer. (I don't have an ulcer, that is a PutneySwopeism) J |
#17
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Help! I've burned up 3 SATA drives today
Jeff Urban wrote:
I have seen some strange ground fault problems. Try to think back, if the drives were not mounted, were they in electrical contact with the case ? One of the drives was in my hand when it burned out. That is the one whose C651 melted. In the other two instances, the metal of the drive was in contact with the metal of the case. I share your worry when a problem just seems to go away. |
#18
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Help! I've burned up 3 SATA drives today
root Inscribed thus:
Baron wrote: root Inscribed thus: I got a used computer on Saturday at a yard sale. I bought it for the case, although it came with a motherboard and power supply but no drives or video card. I put a video card into the machine, along with an IDE drive and the system ran fine. I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I swapped out the power supply for a second unit, and put in another SATA drive. I checked voltage to the molex and it was 11.86 volts and 5.09 volts. It happened again, when I turned on the power I killed the second SATA drive. I took my motherboard out of the new case and put it back in the my old case. Everything runs fine. I put another power supply in the "new" case, this power supply did have SATA power cables. Back into the case went my motherboard. Again, upon power up a third SATA drive was blown. The SATA cables coming from the power supply had an extra orange wire that the molex adapter cables do not have. Three SATA drives down the drain. IDE drives work fine. The last drive that burned up had only the SATA power cable connected. That means the motherboard is out of the picture. I have run out of expendable SATA drives. Any idea of what might be the problem? Possibly open circuit grounds on the power connector... Using my last expendable SATA drive, I retraced my steps as closely as I could remember what I did on Saturday. Starting with the original MB that was in my new case, I put back the original power supply, and plugged in the SATA drive. No Problem. I used the same Chinese SATA adapter cables as I did. I have no idea of what the problem might have been since it is not reproducible. It might be that, in my haste, I didn't push the SATA power plug all the way in and it might have been askew. This is really a stretch because I have pushed on SATA cables for a long time, and I would have had to repeat that screw up two more times. The mental picture was of an OC ground could put 7volts on the drives 5V rail. As an aside I suspect the device which let out the smoke could have been a transient voltage protection device. A bit like a pair of back to back zener diodes. These tend to go SC when they fail. -- Best Regards: Baron. |
#19
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Help! I've burned up 3 SATA drives today
On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root put
finger to keyboard and composed: I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I see this problem several times per week in various storage forums. In fact it's a FAQ: http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html Here are several photo clips: http://www.users.on.net/~fzabkar/HDD/ - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#20
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Help! I've burned up 3 SATA drives today
Franc Zabkar wrote:
On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root put finger to keyboard and composed: I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I see this problem several times per week in various storage forums. In fact it's a FAQ: http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html Here are several photo clips: http://www.users.on.net/~fzabkar/HDD/ - Franc Zabkar Thanks. I will clean out the debris and see if the drive works. I had already put the drives in the recycle bin. |
#21
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Help! I've burned up 3 SATA drives today
root wrote:
Franc Zabkar wrote: On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root put finger to keyboard and composed: I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I see this problem several times per week in various storage forums. In fact it's a FAQ: http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html Here are several photo clips: http://www.users.on.net/~fzabkar/HDD/ - Franc Zabkar Thanks. I will clean out the debris and see if the drive works. I had already put the drives in the recycle bin. Well that was really worthwhile. First I tried the drive that I saw burning. I clipped out the burned part and removed all the parts. The drive came alive and, apart from being sensitive to spikes, is working. I had caught the other two drives before the part burned up completely. No problem, when I connected them up the fuse finished its burn and was easy to identify. Again I clipped the fuse out, cleaned up the debris, and both drives were seen. If the drives had contained vital information I guess this would give me a chance to pull the data. Thanks, this has been very informative. I hope those following this thread can profit. I will scrap the power supply that is the likely cause of the spikes. |
#22
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Help! I've burned up 3 SATA drives today
root Inscribed thus:
root wrote: Franc Zabkar wrote: On Tue, 14 Feb 2012 01:36:27 +0000 (UTC), root put finger to keyboard and composed: I replaced the motherboard with one known to be good: I pulled it from a working computer. I wanted to be able to use SATA drives in the "new" case. The power supply did not have any SATA power cables so I used the molex-sata power adapter cables. When I turned the system on with the first SATA drive in the system a component on the drive smoked and the drive is dead. The component is a surface mount plastic two-terminal (I think) device about 1/8 x 3/16 inch. I can just barely read C651 on the device. I see this problem several times per week in various storage forums. In fact it's a FAQ: http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html Here are several photo clips: http://www.users.on.net/~fzabkar/HDD/ - Franc Zabkar Thanks. I will clean out the debris and see if the drive works. I had already put the drives in the recycle bin. Well that was really worthwhile. First I tried the drive that I saw burning. I clipped out the burned part and removed all the parts. The drive came alive and, apart from being sensitive to spikes, is working. I had caught the other two drives before the part burned up completely. No problem, when I connected them up the fuse finished its burn and was easy to identify. Again I clipped the fuse out, cleaned up the debris, and both drives were seen. If the drives had contained vital information I guess this would give me a chance to pull the data. Thanks, this has been very informative. I hope those following this thread can profit. I will scrap the power supply that is the likely cause of the spikes. That sort of confirms an open ground issue ! Though I don't think the PSU itself is the culprit. -- Best Regards: Baron. |
#23
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Help! I've burned up 3 SATA drives today
On Thu, 16 Feb 2012 19:26:26 +0000 (UTC), root put
finger to keyboard and composed: I had already put the drives in the recycle bin. Hopefully you really did mean "put" rather than "throw". :-) - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#24
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Help! I've burned up 3 SATA drives today
On Thu, 16 Feb 2012 19:57:14 +0000 (UTC), root put
finger to keyboard and composed: I had caught the other two drives before the part burned up completely. No problem, when I connected them up the fuse finished its burn and was easy to identify. Again I clipped the fuse out, cleaned up the debris, and both drives were seen. It's not a fuse, it's a diode. A fuse goes open when it fails, whereas the TVS diode goes short circuit. A fuse is in series with the supply, whereas a TVS diode is in parallel with it, reverse biased, of course. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#25
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Help! I've burned up 3 SATA drives today
I haven't seen the D-Vine case mentioned, but various problems that have
surfaced over the years have been related to numerous required ground points, primarily on large circuit boards (in various types of equipment) including motherboards. Board designers sometimes don't connect critical/required ground points with circuit traces. All of the mounting screws on some motherboards were required for proper connection of the ground points.. and in some instances, case backplates may not have had threaded holes in the correct locations, so some of the screws for the metal mounting posts (standoffs) were casually omitted by DIY computer builders, and the boards would appear to be defective. Another example is ground shields in other types of equipment (RCA), where the solder around the shield tabs would crack, and the equiment would fail to operate, due to the circuit board grounds needing to be tied together by shield mounting tabs. In various types of equipment where several voltage potentials exist within certain sections of the circuitry, when a critical ground point is left open the likelyhood that a required ground/zero-volts-point potential can float (positive or negative). On motherboards particularly, ground points may not be clearly marked as critical circuit connections, whereas required safety ground points typically will be marked in equipment with hazardous voltages. -- Cheers, WB .............. "root" wrote in message ... Big advance since my last post. I scrounged up another expendable SATA drive and powered up the system with the new ThermalTake PS. All went well. That gave me the courage to put in two more SATA drives and the system is running now with all three drives in. No progress in resolving the 3 burned drives but my immediate goal of bringing up the system in the new case is near complete. All this, BTW, was because of the case: it is a D-Vine Home theater case. Something suitable for putting in a living room home entertainment system. |
#26
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Help! I've burned up 3 SATA drives today
Yes, the ground thingie(s). I would like to think this was caused more
by something connected that shouldn't be rather than the other way around. However now we know that what fried was a protection diode. Could it have been across what was suppose dto be 3.3V but was 5V ? What would they have in there, a 3.9V zener ? If I did the math right, feeding a 3.3V device with 5V would result in somewhere aroung 2.3 X the power dissipation is it's analog. Digital may be a bit different, I would think lower, by that I mean a slightly smaller increase in dissipation. This because for the most part heat in a digital device is from the saturation voltage of the semiconductors and the capacitive load on anything that switches.What this all means I think is thast a 3.3V device wil actually work on 5V for a while, how long depends on alot of things. If the components just barely meet spec, minutes or hours, but if you happen to have a really superior specimen, who knows how long it may work, years even. If a similar diode exists for the 12V suply, it is probably 15V, which means one volt will not bother it. In fact driving a motor, it might just be fine with an extra volt, but the next standard zener value up from 3.3 is 3.9. One volt is too much. So if somehow a negative 1V somehow got on the commons, this would explain it. But then how would that thappen ? Concievably if it were an open circuit and chassis ground made that connection, even though it's a bit far fetched as it assumes quite a bit of resistance in that ground. It could happen though, with the uPrecessor drawing alot of amps during bootup. Something like this may actually require a chain of partial failures, just to make that one volt. I agree that this is an intersting subject because the actual cause seems to be elusive. If we don't know why it happened this time there is no way in hell of keeping it from happening again. J |
#27
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Help! I've burned up 3 SATA drives today
Jeff Urban Inscribed thus:
Yes, the ground thingie(s). I would like to think this was caused more by something connected that shouldn't be rather than the other way around. However now we know that what fried was a protection diode. Could it have been across what was suppose dto be 3.3V but was 5V ? What would they have in there, a 3.9V zener ? If I did the math right, feeding a 3.3V device with 5V would result in somewhere aroung 2.3 X the power dissipation is it's analog. Digital may be a bit different, I would think lower, by that I mean a slightly smaller increase in dissipation. This because for the most part heat in a digital device is from the saturation voltage of the semiconductors and the capacitive load on anything that switches.What this all means I think is thast a 3.3V device wil actually work on 5V for a while, how long depends on alot of things. If the components just barely meet spec, minutes or hours, but if you happen to have a really superior specimen, who knows how long it may work, years even. If a similar diode exists for the 12V suply, it is probably 15V, which means one volt will not bother it. In fact driving a motor, it might just be fine with an extra volt, but the next standard zener value up from 3.3 is 3.9. One volt is too much. So if somehow a negative 1V somehow got on the commons, this would explain it. But then how would that thappen ? Concievably if it were an open circuit and chassis ground made that connection, even though it's a bit far fetched as it assumes quite a bit of resistance in that ground. It could happen though, with the uPrecessor drawing alot of amps during bootup. Something like this may actually require a chain of partial failures, just to make that one volt. I agree that this is an intersting subject because the actual cause seems to be elusive. If we don't know why it happened this time there is no way in hell of keeping it from happening again. J I can see where you are going, but consider this... A PC PSU has three major voltage outputs +12, +5, and +3.3. These are the Yellow, Red and Orange wires respectively. Black is common to all three. The Black wires, are normally common to the chassis. That is the negative pole of all three are bonded to the case. The case is also ground and would normally have an earth connected to it. At least in the UK. Now if you place a volt meter between the case and any output you will read an appropriate voltage, 12, 5 or 3.3 volts. Now do the same but connecting the voltmeter between the 12v and 3.3v outputs. Depending upon which way round the meter test leads are you will read + or - 8.7 volts. Do the same with any pair and you will see a voltage equal to the difference between the pair. This is exactly the scenario if the ground was OC on the sata drive or if any other device had an OC ground. -- Best Regards: Baron. |
#28
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Help! I've burned up 3 SATA drives today
Baron wrote:
This is exactly the scenario if the ground was OC on the sata drive or if any other device had an OC ground. The molex connectors have two ground pins. I have seen times that one of the pins is pushed out of the connector, but not both. In my case, neither of the ground pins were pushed out. |
#29
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Help! I've burned up 3 SATA drives today
root Inscribed thus:
Baron wrote: This is exactly the scenario if the ground was OC on the sata drive or if any other device had an OC ground. The molex connectors have two ground pins. I have seen times that one of the pins is pushed out of the connector, but not both. In my case, neither of the ground pins were pushed out. Yes I've seen that happen many times. I've always replaced bad pins, though I don't recall having to replace many female pins. -- Best Regards: Baron. |
#30
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Help! I've burned up 3 SATA drives today
On 15/02/2012 21:49, Mike Tomlinson wrote:
En el , escribió: I intend to pursue an explanation of what happened. If I find out I will post here. Thanks. Would be very interesting to know what it was. I've done the same thing with a Molex/SATA converter. To my shame, I put the Molex connector in upside down which lets the smoke out of a SATA drive quite effectively. Cheapo Molex connectors are not foolproof in their keying. Might be useful if you see if you could have fitted yours upside down (with the power off :-) ) Chris K |
#31
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Help! I've burned up 3 SATA drives today
Chris K wrote:
On 15/02/2012 21:49, Mike Tomlinson wrote: En el , escribió: I intend to pursue an explanation of what happened. If I find out I will post here. Thanks. Would be very interesting to know what it was. I've done the same thing with a Molex/SATA converter. To my shame, I put the Molex connector in upside down which lets the smoke out of a SATA drive quite effectively. Cheapo Molex connectors are not foolproof in their keying. Might be useful if you see if you could have fitted yours upside down (with the power off :-) ) Chris K I just tried the test using one of the molex-sata cables and one of the same power supplies I used. I couldn't get the two together upside down. Moreover, I almost always have trouble lining up make and female parts in a molex connector. The damned pins wiggle independently, so I have to look carefully. |
#32
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Help! I've burned up 3 SATA drives today
It's good to see you posting in SER from time to time J.. always found your
replies concise and explained wrt hands-on experience and knowledgeable background. Yeah, when all the acceptable design tolerances of voltages and component values are taken into consideration (not even considering quality control issues) for almost any peculiar/odd scenario, it generally depends upon a lot of different issues. Load testing used PSUs can involve many seemingly wasted hours, but used electronic gear is typically always iffy/suspect, at best, even if it seemed to be in perfect operating condition.. just yesterday. And then there is always the "specifications subject to change" clause for nearly everything manufacured in recent decades. -- Cheers, WB .............. "Jeff Urban" wrote in message ... Yes, the ground thingie(s). I would like to think this was caused more by something connected that shouldn't be rather than the other way around. However now we know that what fried was a protection diode. Could it have been across what was suppose dto be 3.3V but was 5V ? What would they have in there, a 3.9V zener ? If I did the math right, feeding a 3.3V device with 5V would result in somewhere aroung 2.3 X the power dissipation is it's analog. Digital may be a bit different, I would think lower, by that I mean a slightly smaller increase in dissipation. This because for the most part heat in a digital device is from the saturation voltage of the semiconductors and the capacitive load on anything that switches.What this all means I think is thast a 3.3V device wil actually work on 5V for a while, how long depends on alot of things. If the components just barely meet spec, minutes or hours, but if you happen to have a really superior specimen, who knows how long it may work, years even. If a similar diode exists for the 12V suply, it is probably 15V, which means one volt will not bother it. In fact driving a motor, it might just be fine with an extra volt, but the next standard zener value up from 3.3 is 3.9. One volt is too much. So if somehow a negative 1V somehow got on the commons, this would explain it. But then how would that thappen ? Concievably if it were an open circuit and chassis ground made that connection, even though it's a bit far fetched as it assumes quite a bit of resistance in that ground. It could happen though, with the uPrecessor drawing alot of amps during bootup. Something like this may actually require a chain of partial failures, just to make that one volt. I agree that this is an intersting subject because the actual cause seems to be elusive. If we don't know why it happened this time there is no way in hell of keeping it from happening again. J |
#33
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Help! I've burned up 3 SATA drives today
Jeff Urban wrote: think that somewhere down the line you might wind up blowing another one. I think any further testing should be done with a dummy load! -- Reply in group, but if emailing add one more zero, and remove the last word. |
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