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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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Oxidisation of Seagate & WDC PCBs
I came across a reference to this Russian forum thread in a WDC forum:
http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator: http://translate.google.com/translate_t?sl=ru&tl=en The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. The drives were used in typical office and home environments, and are about a year old. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Is this the fallout from RoHS? Surely it's not the result of some cost saving measure? - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#2
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
I came across a reference to this Russian forum thread in a WDC forum: http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator: http://translate.google.com/translate_t?sl=ru&tl=en The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. The drives were used in typical office and home environments, and are about a year old. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Is this the fallout from RoHS? Surely it's not the result of some cost saving measure? The silver ones are not oxydized. Silver reacts with sulphur, not oxygen. It is normal and cannot really prevented. It is also not a problem in contacts that are not used, as the process stops itselft after at thin coating is reached. The golden ones look like the same thing to me. Maybe the used a high silver content gold here. Sorry, I am noch a chemist. But my parents used to deal in silver jewelery and the look is characteristic. I suspect air pollution as the root cause. As I said, it is not a problem in this case, the sulphurisarion (?) process will not eat through the traces. They are rather better protected with this. It would be a problem on the connectors though. But they will have better and thicker gold anyways. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#3
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
On Apr 8, 12:11*am, Franc Zabkar wrote:
I came across a reference to this Russian forum thread in a WDC forum:http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator:http://translate.google.com/translate_t?sl=ru&tl=en The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. The drives were used in typical office and home environments, and are about a year old. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Is this the fallout from RoHS? Maybe not. There are other known culprits, like the drywall (gypsum board, sheetrock... whatever it's called in your region) that outgasses hydrogen sulphide. Some US construction of a few years ago is so bad with this toxic and corrosive gas emission that demolition of nearly-new construction is called for. Corrosion of nearby copper is one of the symptoms of the nasty product. |
#4
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Oxidisation of Seagate & WDC PCBs
Hi!
The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. I've seen minor occurrences of it and wondered what it was, but only on the "one use" contact pads on the bottom of the drive's PCB. (My guess is that these are used to set the drive up for its first time use and do some basic tests to assure the new drive is functional.) Some drives had more of this apparent oxidation than others, but all of the ones I've seen had it from the moment they were removed from the package. It hasn't gotten any worse and these drives continue to operate properly. I checked a few at random and did not find a similar effect on the contacts going to the spindle motor or headstack. William |
#5
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
Franc Zabkar wrote: I came across a reference to this Russian forum thread in a WDC forum: http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator: http://translate.google.com/translate_t?sl=ru&tl=en The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. The drives were used in typical office and home environments, and are about a year old. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Does this mean we should apply contact protector, such as De-Oxit, to the PCBs to prevent corrosion? |
#6
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage larry moe 'n curly wrote:
Franc Zabkar wrote: I came across a reference to this Russian forum thread in a WDC forum: http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator: http://translate.google.com/translate_t?sl=ru&tl=en The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. The drives were used in typical office and home environments, and are about a year old. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Does this mean we should apply contact protector, such as De-Oxit, to the PCBs to prevent corrosion? No need. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#7
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
On Thu, 8 Apr 2010 14:03:39 -0700 (PDT), whit3rd
put finger to keyboard and composed: On Apr 8, 12:11*am, Franc Zabkar wrote: Is this the fallout from RoHS? Maybe not. There are other known culprits, like the drywall (gypsum board, sheetrock... whatever it's called in your region) that outgasses hydrogen sulphide. Some US construction of a few years ago is so bad with this toxic and corrosive gas emission that demolition of nearly-new construction is called for. Corrosion of nearby copper is one of the symptoms of the nasty product. It's not just Russia that has this problem. The same issue comes up frequently at the HDD Guru forums. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#8
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
On Thu, 8 Apr 2010 20:20:55 -0700 (PDT), "larry moe 'n curly"
put finger to keyboard and composed: Franc Zabkar wrote: I came across a reference to this Russian forum thread in a WDC forum: http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator: http://translate.google.com/translate_t?sl=ru&tl=en The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. The drives were used in typical office and home environments, and are about a year old. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Does this mean we should apply contact protector, such as De-Oxit, to the PCBs to prevent corrosion? One of the sticky threads at the HDD Guru forums recommends that the preamp contacts on WD drives be scrubbed clean with a soft white pencil eraser whenever they come in for data recovery. - Franc Zabkar -- Please remove one 'i' from my address when replying by email. |
#9
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Franc Zabkar wrote:
On Thu, 8 Apr 2010 20:20:55 -0700 (PDT), "larry moe 'n curly" put finger to keyboard and composed: Franc Zabkar wrote: I came across a reference to this Russian forum thread in a WDC forum: http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator: http://translate.google.com/translate_t?sl=ru&tl=en The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. The drives were used in typical office and home environments, and are about a year old. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Does this mean we should apply contact protector, such as De-Oxit, to the PCBs to prevent corrosion? One of the sticky threads at the HDD Guru forums recommends that the preamp contacts on WD drives be scrubbed clean with a soft white pencil eraser whenever they come in for data recovery. That sounds like BS to me. A soft pencil eraser cannot remove silver sulfide, it is quite resilient. There are special silver cleaning cloths that will do the trick. Still, I doubt that this is a problem. It shoud not crawl between working contacts, only unused ones. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#10
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
On Thu, 08 Apr 2010 17:11:39 +1000, Franc Zabkar
wrote: I came across a reference to this Russian forum thread in a WDC forum: http://maccentre.ru/board/viewtopic....70953&start=15 Here is Google's translator: http://translate.google.com/translate_t?sl=ru&tl=en A better way to do this is to drag the English translation tool to the tool browser bar: http://translate.google.com/translate_tools The browser will automagically ask if you want to translate any foreign language web page that you view. The thread discusses oxidisation of contact pads in current Seagate and Western Digital hard drives. It's not oxidation. Oxides of both tin and lead are white in color. My guess(tm) is lead sulphide (galena), as lead sulphate and tin sulphate are usually white. http://en.wikipedia.org/wiki/Lead%28II%29_sulfide It's difficult to tell from the photos if the PCB contacts are gold or tin-silver. It's also difficult to tell if there was a mix of contact materials. Mixing gold and tin contacts usually results in black crud and fretting: http://www.tycoelectronics.com/documentation/whitepapers/pdf/p316-90.pdf http://www.tycoelectronics.com/documentation/whitepapers/pdf/p154-74.pdf (see Fig 3). Contact material galvanic mismatch is another possibility. The drives were used in typical office and home environments, and are about a year old. Another possible culprit is a contaminated or poorly washed PC board. The typical kitchen environment will also cause a problem. I see it on machines and drives fairly often. If necessary, I just clean the contacts with a pink pencil eraser, and reassemble. I've NEVER had a drive failure that was directly attributed to such contact corrosion. It's usually something else that kills the drive. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Is this the fallout from RoHS? Surely it's not the result of some cost saving measure? Nope. If the contacts were tin-silver, 5% lead, or one of the other low lead alloys, the corrosion would probably be white or light gray in color. The dark black suggests there's at least some lead involved or possibly dissimilar contact material. -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#11
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Jeff Liebermann wrote:
On Thu, 08 Apr 2010 17:11:39 +1000, Franc Zabkar wrote: [...] I've NEVER had a drive failure that was directly attributed to such contact corrosion. It's usually something else that kills the drive. I think people are jumping to conclusion, because the discolorarion is what they can see (and think they understand). There is a posting in this thread with a person that has had a 3-way RAID1 fail and attributes it to the contact discoloration. Now, whith a slow chemical process, the required level of synchronicity is as unlikely that calling it impossible is fair. The thread has several detailed photos. All except the older tinned PCB appear to show evidence of serious corrosion. Is this the fallout from RoHS? Surely it's not the result of some cost saving measure? Nope. If the contacts were tin-silver, 5% lead, or one of the other low lead alloys, the corrosion would probably be white or light gray in color. The dark black suggests there's at least some lead involved or possibly dissimilar contact material. Actually pure silver also sulfidizes (?) in this way. The look is very characteristic. I think this is silver plating we see. It is typically not a problem on contacts that are in use, it does not crawl between contact points. I suspect in the observed instances, this is a purely aestetic problem and has no impact on HDD performance or reliability whatsoever. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#12
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In article , Arno
writes That sounds like BS to me. A soft pencil eraser cannot remove silver sulfide, it is quite resilient. It's a technique that has been used on edge connectors for many years. -- Mike Tomlinson |
#13
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
On Mon, 12 Apr 2010 13:16:00 +0100 Mike Tomlinson
wrote in Message id: : In article , Arno writes That sounds like BS to me. A soft pencil eraser cannot remove silver sulfide, it is quite resilient. It's a technique that has been used on edge connectors for many years. Yup, and it works. I learned the technique when servicing Multibus I systems, and still use it to this day. |
#14
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
On Sat, 10 Apr 2010 22:33:49 +0000 (UTC), Sergey Kubushyn
wrote: I'm right here in the US and I had 3 of 3 WD 1TB drives failed at the same time in RAID1 thus making the entire array dead. That's the real problem with RAID using identical drives. When one drive dies, the others are highly likely to follow. I had that experience in about 2003 with a Compaq something Unix server running SCSI RAID 1+0 (4 drives). One drive failed, and I replacing it with a backup drive, which worked. The drive failure was repeated a week later when a 2nd drive failed. When I realized what was happening, I ran a complete tape backup, replaced ALL the drives, and restored from the the backup. That was just in time as both remaining drives were dead when I tested them a few weeks later. I've experienced similar failures since then, and have always recommended replacing all the drives, if possible (which is impractical for large arrays). -- Jeff Liebermann 150 Felker St #D http://www.LearnByDestroying.com Santa Cruz CA 95060 http://802.11junk.com Skype: JeffLiebermann AE6KS 831-336-2558 |
#15
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote:
In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Franc Zabkar wrote: On Thu, 8 Apr 2010 14:03:39 -0700 (PDT), whit3rd put finger to keyboard and composed: On Apr 8, 12:11?am, Franc Zabkar wrote: Is this the fallout from RoHS? Maybe not. There are other known culprits, like the drywall (gypsum board, sheetrock... whatever it's called in your region) that outgasses hydrogen sulphide. Some US construction of a few years ago is so bad with this toxic and corrosive gas emission that demolition of nearly-new construction is called for. Corrosion of nearby copper is one of the symptoms of the nasty product. It's not just Russia that has this problem. The same issue comes up frequently at the HDD Guru forums. I'm right here in the US and I had 3 of 3 WD 1TB drives failed at the same time in RAID1 thus making the entire array dead. It is not that you can simply buff that dark stuff off and you're good to go. Drive itself tries to recover from failures by rewriting service info (remapping etc.) but connection is unreliable and it trashes the entire disk beyound repair. Then you have that infamous "click of death"... BTW, it is not just WD; others are also that bad. It is extremly unlikely for a slow chemical process to achive this level of syncronicity. About as unlikely that it would be fair to call it impossible Your array died from a different cause that would affect all drives simultaneously, such as a power spike. Yes, they did not die from contacts oxidation at that very same moment. I can not even tell they all died the same month--that array might've been running in degraded mode with one drive dead, then after some time second drive died but it was still running on one remaining drive. And only when the last one crossed the Styx the entire array went dead. Ah, I see. I did misunderstand that. May still be something else but the contacts are a possible explanation with that. I don't use Windows so my machines are never turned off unless there is a real need for this. And they are rarely updated once they are up and running so there is no reboots. Typical uptime is more than a year. So your disks worked and then refused to restart? Or you are running a RAID1 without monitoring? I don't know though how I could miss a degradation alert if there was any. Well, if it is Linux with mdadm, it only sends one email per degradation event in the default settings. All 3 drives in the array simply failed to start after reboot. There were some media errors reported before reboot but all drives somehow worked. Then the system got rebooted and all 3 drives failed with the same "click of death." The mechanism here is not that oxidation itself killed the drives. It never happens that way. It was a main cause of a failure, but drives actually performed suicide like body immune system kills that body when overreacting to some kind of hemorrargic fever or so. The probable sequence is something like this: - Drives run for a long time with majority of the files never accessed so it doesn't matter if that part of the disk where they are stored is bad or not I run long smart selftest on all my drives (RAID or no) every 14 days to prevent that. Works well. - When the system is rebooted RAID array assembly is performed - While this assembly is being performed a number of sectors on a drive found to be defective and drive tries to remap them - Such action involves rewriting service information - Read/write operations are unreliable because of failing head contacts so the service areas become filled with garbage - Once the vital service information is damaged the drive is essentially dead because its controller can not read vital data to even start the disk - The only hope for the controller to recover is to repeat the read in hope that it might somehow get read. This is that infamous "click of death" sound when drive tries to read the info again and again. There is no way it can recover because that data are trashed. - Drives do NOT fail while they run, the failure happens on the next reboot. The damage that would kill the drives on that reboot happened way before that reboot though. That suicide also can happen when some old file that was not accessed for ages is read. That attempt triggers the suicide chain. Yes, that makes sense. However you should do surface scans on RAIDed disks regularly, e.g. by long SMART selftests. This will catch weak sectors early and other degradation as well. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#16
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Jeff Liebermann wrote:
On Sat, 10 Apr 2010 22:33:49 +0000 (UTC), Sergey Kubushyn wrote: I'm right here in the US and I had 3 of 3 WD 1TB drives failed at the same time in RAID1 thus making the entire array dead. That's the real problem with RAID using identical drives. When one drive dies, the others are highly likely to follow. I had that experience in about 2003 with a Compaq something Unix server running SCSI RAID 1+0 (4 drives). One drive failed, and I replacing it with a backup drive, which worked. The drive failure was repeated a week later when a 2nd drive failed. When I realized what was happening, I ran a complete tape backup, replaced ALL the drives, and restored from the the backup. That was just in time as both remaining drives were dead when I tested them a few weeks later. I've experienced similar failures since then, and have always recommended replacing all the drives, if possible (which is impractical for large arrays). For high reliability requirements it is also a good idea to use different brand drives, to get a better distributed times between failures. Some people have reported the effect you see. A second thing that can cause this effect is when the disks are not regularly surface scanned. I run a long SMART selftest on all disks, also the RAIDed ones for this every 14 days. The remaining disks are under more stress during array rebuild, especially if the have weak sectors. This additional load can cause the remaining drives to fail a lot faster, in the wort case during array rebuild. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#17
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Mike Tomlinson wrote:
In article , Arno writes That sounds like BS to me. A soft pencil eraser cannot remove silver sulfide, it is quite resilient. It's a technique that has been used on edge connectors for many years. It works with a harder eraser and it works for tin contacts with a soft one. But it does not work for silver contacts, you need to have at least some sand in th eraser for that. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#18
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
Sergey Kubushyn wrote:
In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Franc Zabkar wrote: On Thu, 8 Apr 2010 14:03:39 -0700 (PDT), whit3rd put finger to keyboard and composed: On Apr 8, 12:11?am, Franc Zabkar wrote: Is this the fallout from RoHS? Maybe not. There are other known culprits, like the drywall (gypsum board, sheetrock... whatever it's called in your region) that outgasses hydrogen sulphide. Some US construction of a few years ago is so bad with this toxic and corrosive gas emission that demolition of nearly-new construction is called for. Corrosion of nearby copper is one of the symptoms of the nasty product. It's not just Russia that has this problem. The same issue comes up frequently at the HDD Guru forums. I'm right here in the US and I had 3 of 3 WD 1TB drives failed at the same time in RAID1 thus making the entire array dead. It is not that you can simply buff that dark stuff off and you're good to go. Drive itself tries to recover from failures by rewriting service info (remapping etc.) but connection is unreliable and it trashes the entire disk beyound repair. Then you have that infamous "click of death"... BTW, it is not just WD; others are also that bad. It is extremly unlikely for a slow chemical process to achive this level of syncronicity. About as unlikely that it would be fair to call it impossible Your array died from a different cause that would affect all drives simultaneously, such as a power spike. Yes, they did not die from contacts oxidation at that very same moment. I can not even tell they all died the same month--that array might've been running in degraded mode with one drive dead, then after some time second drive died but it was still running on one remaining drive. And only when the last one crossed the Styx the entire array went dead. Ah, I see. I did misunderstand that. May still be something else but the contacts are a possible explanation with that. I don't think it is something else but everything is possible... I don't use Windows so my machines are never turned off unless there is a real need for this. And they are rarely updated once they are up and running so there is no reboots. Typical uptime is more than a year. So your disks worked and then refused to restart? Or you are running a RAID1 without monitoring? They failed during weekly full backup. One of the files read failed and they entered that infinite loop of restarting themself and retrying. Root filesystem was also on that RAID1 array so there was no other choice than to reboot. And on that reboot all 3 drives failed to start with the same "click of death" syndrome. I don't know though how I could miss a degradation alert if there was any. Well, if it is Linux with mdadm, it only sends one email per degradation event in the default settings. Yep, I probably missed it when shoveling through mountains of spam. All 3 drives in the array simply failed to start after reboot. There were some media errors reported before reboot but all drives somehow worked. Then the system got rebooted and all 3 drives failed with the same "click of death." The mechanism here is not that oxidation itself killed the drives. It never happens that way. It was a main cause of a failure, but drives actually performed suicide like body immune system kills that body when overreacting to some kind of hemorrargic fever or so. The probable sequence is something like this: - Drives run for a long time with majority of the files never accessed so it doesn't matter if that part of the disk where they are stored is bad or not I run long smart selftest on all my drives (RAID or no) every 14 days to prevent that. Works well. - When the system is rebooted RAID array assembly is performed - While this assembly is being performed a number of sectors on a drive found to be defective and drive tries to remap them - Such action involves rewriting service information - Read/write operations are unreliable because of failing head contacts so the service areas become filled with garbage - Once the vital service information is damaged the drive is essentially dead because its controller can not read vital data to even start the disk - The only hope for the controller to recover is to repeat the read in hope that it might somehow get read. This is that infamous "click of death" sound when drive tries to read the info again and again. There is no way it can recover because that data are trashed. - Drives do NOT fail while they run, the failure happens on the next reboot. The damage that would kill the drives on that reboot happened way before that reboot though. That suicide also can happen when some old file that was not accessed for ages is read. That attempt triggers the suicide chain. Yes, that makes sense. However you should do surface scans on RAIDed disks regularly, e.g. by long SMART selftests. This will catch weak sectors early and other degradation as well. I know but I simply didn't think all 3 drives can fail... I thought I have enough redundancy because I put not 2 but 3 drives in that RAID1... And I did have something like a test with regular weekly full backup that reads all the files (not the entire disk media but at least all the files on it) and that was that backup that triggered disk suicide. Anyway lesson learned and I'm taking additional measures now. It was not a very good experience loosing some of my work... BTW, I took a look at brand new WDC WD5000YS-01MPB1 drives, right out of the sealed bags with silica gel and all 4 of those had their contacts already oxidized with a lot of black stuff. That makes me very suspicious that conspiracy theory might be not all that crazy--that oxidation seems to be pre-applied by the manufacturer. MUCH more likely that someone ****ed up in the factory. |
#19
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote:
[...] That suicide also can happen when some old file that was not accessed for ages is read. That attempt triggers the suicide chain. Yes, that makes sense. However you should do surface scans on RAIDed disks regularly, e.g. by long SMART selftests. This will catch weak sectors early and other degradation as well. I know but I simply didn't think all 3 drives can fail... I thought I have enough redundancy because I put not 2 but 3 drives in that RAID1... And I did have something like a test with regular weekly full backup that reads all the files (not the entire disk media but at least all the files on it) and that was that backup that triggered disk suicide. Anyway lesson learned and I'm taking additional measures now. It was not a very good experience loosing some of my work... Yes, I can imagine. I have my critical stuff also on a 3 way RAID1, but with long SMART selftests every 2 weeks and 3 different drives, two from WD and one from Samsung. One additional advantage of the long SMART selftest is that with smartd you will get a warning email on every failing test, i.e. one every two weeks. For additional warning you can also run a daily short test, e.g.. BTW, I took a look at brand new WDC WD5000YS-01MPB1 drives, right out of the sealed bags with silica gel and all 4 of those had their contacts already oxidized with a lot of black stuff. That makes me very suspicious that conspiracy theory might be not all that crazy--that oxidation seems to be pre-applied by the manufacturer. Urgh. These bags are airtight. No way the problem happened on your side then. My two weeks old WD5000AADS-00S9B0 looks fine on the top of the PCB. I think I will have a look underneath later. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#20
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote:
In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: [...] That suicide also can happen when some old file that was not accessed for ages is read. That attempt triggers the suicide chain. Yes, that makes sense. However you should do surface scans on RAIDed disks regularly, e.g. by long SMART selftests. This will catch weak sectors early and other degradation as well. I know but I simply didn't think all 3 drives can fail... I thought I have enough redundancy because I put not 2 but 3 drives in that RAID1... And I did have something like a test with regular weekly full backup that reads all the files (not the entire disk media but at least all the files on it) and that was that backup that triggered disk suicide. Anyway lesson learned and I'm taking additional measures now. It was not a very good experience loosing some of my work... Yes, I can imagine. I have my critical stuff also on a 3 way RAID1, but with long SMART selftests every 2 weeks and 3 different drives, two from WD and one from Samsung. One additional advantage of the long SMART selftest is that with smartd you will get a warning email on every failing test, i.e. one every two weeks. For additional warning you can also run a daily short test, e.g.. No matter what you do you can not prevent an occasional disaster One MUST remember that "backup" in not a noun but a verb in imperative. Indeed. BTW, I took a look at brand new WDC WD5000YS-01MPB1 drives, right out of the sealed bags with silica gel and all 4 of those had their contacts already oxidized with a lot of black stuff. That makes me very suspicious that conspiracy theory might be not all that crazy--that oxidation seems to be pre-applied by the manufacturer. Urgh. These bags are airtight. No way the problem happened on your side then. My two weeks old WD5000AADS-00S9B0 looks fine on the top of the PCB. I think I will have a look underneath later. Those 4 were fine on the top of PCB. Black stuff was underneath, on those pads contacting with springy heads pins. Mine is fine on both sides. However there is a quite a bit of contact area that looks and feels silver-plated to me, most notably areound the screws and on the bottom the contacts to the head assembly. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#21
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote:
In sci.electronics.repair Arno wrote: [...] Those 4 were fine on the top of PCB. Black stuff was underneath, on those pads contacting with springy heads pins. Mine is fine on both sides. However there is a quite a bit of contact area that looks and feels silver-plated to me, most notably areound the screws and on the bottom the contacts to the head assembly. That makes me wonder why are they silver-plated. It is definitely not the best material longevitywise, especially for such low-level signals. It makes me even more suspicious and adds to the conspiracy theory. Well, maybe. However I tend to think that "never attribute to malice what can be adequately explained by stupidity" may apply. These contacts should be gold plated with high quality gold. It is also possible that the HDD vibration (always present with a running HDD) and thermal variation allows the process to creep between the contacts and kill them. Maybe a young, inexperienced engineer was hired to replace an older, experienced (but more expensive one) and that person made a pretty bad judgement call due to inexperience, wanting to save a few cents on the design. I have to say that the last time I saw silver plating as contact protection was in vaccuum tube equipment. Modern electronics typically uses Gold, or Tin for low insertion cycle contacts. I also found a statement on Wikipaedia that silver plated copper, once the copper is exposed in a place, will rapidly corrode all over because of some electro-chemical process. No idea whether this is true or not. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#22
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
Sergey Kubushyn wrote:
In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: [...] That suicide also can happen when some old file that was not accessed for ages is read. That attempt triggers the suicide chain. Yes, that makes sense. However you should do surface scans on RAIDed disks regularly, e.g. by long SMART selftests. This will catch weak sectors early and other degradation as well. I know but I simply didn't think all 3 drives can fail... I thought I have enough redundancy because I put not 2 but 3 drives in that RAID1... And I did have something like a test with regular weekly full backup that reads all the files (not the entire disk media but at least all the files on it) and that was that backup that triggered disk suicide. Anyway lesson learned and I'm taking additional measures now. It was not a very good experience loosing some of my work... Yes, I can imagine. I have my critical stuff also on a 3 way RAID1, but with long SMART selftests every 2 weeks and 3 different drives, two from WD and one from Samsung. One additional advantage of the long SMART selftest is that with smartd you will get a warning email on every failing test, i.e. one every two weeks. For additional warning you can also run a daily short test, e.g.. No matter what you do you can not prevent an occasional disaster One MUST remember that "backup" in not a noun but a verb in imperative. Indeed. BTW, I took a look at brand new WDC WD5000YS-01MPB1 drives, right out of the sealed bags with silica gel and all 4 of those had their contacts already oxidized with a lot of black stuff. That makes me very suspicious that conspiracy theory might be not all that crazy--that oxidation seems to be pre-applied by the manufacturer. Urgh. These bags are airtight. No way the problem happened on your side then. My two weeks old WD5000AADS-00S9B0 looks fine on the top of the PCB. I think I will have a look underneath later. Those 4 were fine on the top of PCB. Black stuff was underneath, on those pads contacting with springy heads pins. Mine is fine on both sides. However there is a quite a bit of contact area that looks and feels silver-plated to me, most notably areound the screws and on the bottom the contacts to the head assembly. That makes me wonder why are they silver-plated. It is definitely not the best material longevitywise, especially for such low-level signals. Likely just some fool's reaction to the price of gold. It makes me even more suspicious and adds to the conspiracy theory. Nope. |
#23
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Sjouke Burry wrote:
Sergey Kubushyn wrote: In sci.electronics.repair Arno wrote: [...] Mine is fine on both sides. However there is a quite a bit of contact area that looks and feels silver-plated to me, most notably areound the screws and on the bottom the contacts to the head assembly. That makes me wonder why are they silver-plated. It is definitely not the best material longevitywise, especially for such low-level signals. It makes me even more suspicious and adds to the conspiracy theory. You know of course that the black silver layer is still conductive for low level signals?? Silver Silfide is a (bad) conductor? That will help for the R/W signal. However the lines for the moving coil go through the same connector and they need a low resistance path. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#24
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
Arno wrote:
In comp.sys.ibm.pc.hardware.storage Sjouke Burry wrote: Sergey Kubushyn wrote: In sci.electronics.repair Arno wrote: [...] Mine is fine on both sides. However there is a quite a bit of contact area that looks and feels silver-plated to me, most notably areound the screws and on the bottom the contacts to the head assembly. That makes me wonder why are they silver-plated. It is definitely not the best material longevitywise, especially for such low-level signals. It makes me even more suspicious and adds to the conspiracy theory. You know of course that the black silver layer is still conductive for low level signals?? Silver Silfide is a (bad) conductor? Nope. That will help for the R/W signal. However the lines for the moving coil go through the same connector and they need a low resistance path. The black silver layer conducts that fine. |
#25
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote:
In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Arno wrote: [...] Those 4 were fine on the top of PCB. Black stuff was underneath, on those pads contacting with springy heads pins. Mine is fine on both sides. However there is a quite a bit of contact area that looks and feels silver-plated to me, most notably areound the screws and on the bottom the contacts to the head assembly. That makes me wonder why are they silver-plated. It is definitely not the best material longevitywise, especially for such low-level signals. It makes me even more suspicious and adds to the conspiracy theory. Well, maybe. However I tend to think that "never attribute to malice what can be adequately explained by stupidity" may apply. I agree but it looks like there is a pattern here... These contacts should be gold plated with high quality gold. It is also possible that the HDD vibration (always present with a running HDD) and thermal variation allows the process to creep between the contacts and kill them. Maybe a young, inexperienced engineer was hired to replace an older, experienced (but more expensive one) and that person made a pretty bad judgement call due to inexperience, wanting to save a few cents on the design. They did not save anything on that design. Gold plating is a common procedure, it is everywhere, most of card-edge connectors (e.g. PCI) are gold and they even called "gold fingers" by chinese PCB manufacturers. Silver, on the other hand, is almost unheard of and I'm pretty sure PCB makers would charge extra for this if they agree to do it at all. And it is NOT that the entire board is silver-plated; there are gold-plated parts on that same board that makes it have at least 2 different platings so it will be more expensive than simple gold all over. Good points. An exotic process would be more expensive than a common one and two processes instead of one as well. I also happen to know that putting gold directly on silcer is problematic, but putting it directly on copper is fine. At least that is for galvanics on jewelery and if I remember this correctly. I have to say that the last time I saw silver plating as contact protection was in vaccuum tube equipment. Modern electronics typically uses Gold, or Tin for low insertion cycle contacts. Yep. Silver plating was usually used in microwave equipment, HF coils etc. where skin effect was so profound that current only ran through that silver (that was quite thick, btw.) Silver is also used for HIGH CURRENT relay contacts where the corrosion is removed by mechanical action of closing contacts and burned through with high current. That explains it. I have indeed seen it in power relais as well. If you look at low current signal relays with stated minimal current capacity _NONE_ of them have silver contacts. It is usually gold, platinum, rhodium, or a mix thereof. I am all pro Occam's Razor but all this looks like deliberate effort to make it fail after some time. It is NOT easier or cheaper to put silver there because it is an _ADDITIONAL_ step and not so common one. Well, it only makes the required level of stupidity larger, because (if we have this right) they also need to mess up the economic angle. If we assume they are competent, then indeed this looks very much like a deliberate and rather bad design error. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans |
#26
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
Arno wrote:
In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Arno wrote: In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Arno wrote: [...] Those 4 were fine on the top of PCB. Black stuff was underneath, on those pads contacting with springy heads pins. Mine is fine on both sides. However there is a quite a bit of contact area that looks and feels silver-plated to me, most notably areound the screws and on the bottom the contacts to the head assembly. That makes me wonder why are they silver-plated. It is definitely not the best material longevitywise, especially for such low-level signals. It makes me even more suspicious and adds to the conspiracy theory. Well, maybe. However I tend to think that "never attribute to malice what can be adequately explained by stupidity" may apply. I agree but it looks like there is a pattern here... These contacts should be gold plated with high quality gold. It is also possible that the HDD vibration (always present with a running HDD) and thermal variation allows the process to creep between the contacts and kill them. Maybe a young, inexperienced engineer was hired to replace an older, experienced (but more expensive one) and that person made a pretty bad judgement call due to inexperience, wanting to save a few cents on the design. They did not save anything on that design. Gold plating is a common procedure, it is everywhere, most of card-edge connectors (e.g. PCI) are gold and they even called "gold fingers" by chinese PCB manufacturers. Silver, on the other hand, is almost unheard of and I'm pretty sure PCB makers would charge extra for this if they agree to do it at all. And it is NOT that the entire board is silver-plated; there are gold-plated parts on that same board that makes it have at least 2 different platings so it will be more expensive than simple gold all over. Good points. An exotic process would be more expensive than a common one and two processes instead of one as well. I also happen to know that putting gold directly on silcer is problematic, but putting it directly on copper is fine. At least that is for galvanics on jewelery and if I remember this correctly. I have to say that the last time I saw silver plating as contact protection was in vaccuum tube equipment. Modern electronics typically uses Gold, or Tin for low insertion cycle contacts. Yep. Silver plating was usually used in microwave equipment, HF coils etc. where skin effect was so profound that current only ran through that silver (that was quite thick, btw.) Silver is also used for HIGH CURRENT relay contacts where the corrosion is removed by mechanical action of closing contacts and burned through with high current. That explains it. I have indeed seen it in power relais as well. If you look at low current signal relays with stated minimal current capacity _NONE_ of them have silver contacts. It is usually gold, platinum, rhodium, or a mix thereof. I am all pro Occam's Razor but all this looks like deliberate effort to make it fail after some time. It is NOT easier or cheaper to put silver there because it is an _ADDITIONAL_ step and not so common one. Well, it only makes the required level of stupidity larger, because (if we have this right) they also need to mess up the economic angle. If we assume they are competent, then indeed this looks very much like a deliberate and rather bad design error. Or some fool has focussed on the price of gold metal and has lost sight of the fact that more complex pcb manufacturing process negates any advantage by using the cheaper metal. MUCH more likely than any conspiracy to shaft the user. |
#27
Posted to sci.electronics.repair,comp.sys.ibm.pc.hardware.storage
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Oxidisation of Seagate & WDC PCBs
On 30 Apr 2010 23:57:32 GMT, Arno wrote:
In comp.sys.ibm.pc.hardware.storage Sergey Kubushyn wrote: In sci.electronics.repair Sergey Kubushyn wrote: Just took a brand spanking new WD5000AAKS drive out of sealed bag with silica gel and all that stuff. The PCB is all _SILVER_ plated, no gold. And that silver is almost totally black right out of the bag. Not good. Silver really is unsuitable for modern, low voltage, electronics. The last WD disk I bought (a WD5000AADS, 500GB Caviar Green) had mixed gold and silver plating and the silver plating was completely fine, on both sides of the PCB. I just removed the PCB from a WD200EB-75CSF0 20GB drive. Tin plating on both the PCB contacts and the mating pin array going into the HDA assembly. No gold or silver. However, there's one extra item that hasn't entered the discussion. There was a sheet of foam something between the PCB and the HDA. In this case, it was quite clean and dry, but it wouldn't take much for most any liquid to get absorbed by the foam and rot out the board. There was a cut-out hole around the connector area, so there was no common points of contact, but it was close enough that any volatiles would certainly enter the connector area. -- # Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060 # 831-336-2558 # http://802.11junk.com # http://www.LearnByDestroying.com AE6KS |
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