Recovering data from an SSD with a dead controller. - Page 1
Forum section: electronics / projects

author: Ferroto
author_rank: Frequent Contributor
timestamp: August 18, 2015, 10:49:43 am
content: Well my SSD finally kicked the bucket. One day my system was locked up and when I rebooted the BIOS could no longer detect my 120gb Samsung EVO. My theory is that it's the ARM processor that's used for talking to the flash memory due to the fact that it can't even be detected by the bios. Then I started thinking, an SSD is just a glorified flash drive. All it has is a controller which talks to the mainboard and some flash memory. I was wondering if it would be possible to read the data directly from the flash memory bypassing the controller chip all together. Below you see some header holes that are possibly JTAG. I don't know much about JTAG how can I determine if they are JTAG or not without JTAG equipment?First impression there isn't much inside these thingsWelp looks like it's all BGA.

author: Jeroen3
author_rank: Super Contributor
timestamp: August 18, 2015, 11:04:13 am
content: I'm curious if you will succeed. Since ssd's use wear leveling, which basically is randomizing the memory map for those who don't know the algorithm.Are there any professional services for ssd data recovery? I've not seen many.

author: wraper
author_rank: Unknown
timestamp: August 18, 2015, 11:29:47 am
content: No, you won't be able to do this. Data is wear leveled, and in many SSDs encrypted too.

author: helius
author_rank: Super Contributor
timestamp: August 18, 2015, 11:43:57 am
content: The primary purpose of JTAG is testing circuit boards. All of the chips on a board that have JTAG are connected in a chain, so if any of the chips are dead, the chain won't work.

author: Psi
author_rank: Super Contributor
timestamp: August 18, 2015, 11:46:12 am
content: A cracked BGA joint is probably more likely than a failed IC.Try reflow it.

author: Ferroto
author_rank: Frequent Contributor
timestamp: August 18, 2015, 03:35:42 pm
content: Quote from: Psi on August 18, 2015, 11:46:12 amI've never re-flowed anything before how would I go about this. also there's BGA and SMD components on both sides.

author: suicidaleggroll
author_rank: Super Contributor
timestamp: August 18, 2015, 03:48:20 pm
content: Easy - take your most recent backup, restore the data on a new drive, done. If you don't have a backup, then consider this a painful lesson...never trust a HDD/SSD, always have at least 2 copies of any data that can't be easily replaced, at a minimum on separate drives, preferably in separate physical locations.

author: Jeroen3
author_rank: Super Contributor
timestamp: August 18, 2015, 04:08:58 pm
content: Putting the board in a regular oven for a while seemed to have worked with the GTX 8800 for a lot of people. It might just work for you.Actual re soldering involves hot air or infrared, reballing and accurate placement. I wouldn't go there.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 18, 2015, 04:24:16 pm
content: Soldering temperatures cause rapid degradation of stored data, I wonder if it would even remember anything useful afterwards.SSDs are simply less reliable, even with leveling; I wouldn't operate one without a backup, period. That's why I got a RAID5 pair to keep frequent backups (plus whatever bulk storage I need).Tim

author: suicidaleggroll
author_rank: Super Contributor
timestamp: August 18, 2015, 04:29:54 pm
content: Quote from: T3sl4co1l on August 18, 2015, 04:24:16 pmI disagree completely. I have a lot of experience with HDDs and SSDs, and the SSDs are noticeably more reliable than the HDDs. I can count on a failure rate of about 10-15% within the first 5 years with HDDs. So far with SSDs (40+ under my control with the oldest dating back over 6 years) that's looking more like 2-4%. That said, they can still fail, just like HDDs do.Quote from: T3sl4co1l on August 18, 2015, 04:24:16 pmYou shouldn't operate any SSD/HDD without regular backups, it's just common sense.

author: madires
author_rank: Super Contributor
timestamp: August 18, 2015, 05:05:10 pm
content: Quote from: suicidaleggroll on August 18, 2015, 04:29:54 pmIIRC, long term statistics from a data center showed that SSDs got about twice the failure rate of HDDs. If you compare SSDs with desktop HDDs it's about the same.

author: Rasz
author_rank: Super Contributor
timestamp: August 18, 2015, 05:14:50 pm
content: Quote from: Jeroen3 on August 18, 2015, 04:08:58 pmI used to give that advice, until this happened:https://www.eevblog.com/forum/repair/'just-reflow-it'-or-how-not-to-do-it/Quote from: T3sl4co1l on August 18, 2015, 04:24:16 pmI resoldered tens (maybe a hundred by now) nor and nand chips with hotair, and never had a data loss. You would probably need to cook one for couple of minutes, or operate of one of the bad designs like Samsung flash used in 840 drives (loss of charge after a ~month and subsequent VERY slow operation).btw there was an invention in 2012 that incorporated heating element directly on the NAND substrate to periodically cook memory cells healing micro cracks caused by wear.http://www.extremetech.com/computing/142096-self-healing-self-heating-flash-memory-survives-more-than-100-million-cycleslooks like it was too expensive, or too reliable

author: wraper
author_rank: Unknown
timestamp: August 18, 2015, 05:25:02 pm
content: AFAIK, with SSDs there are more issues when firmware just locks out rather than actual hardware failures.

author: Rasz
author_rank: Super Contributor
timestamp: August 18, 2015, 05:32:14 pm
content: I forgot one thing in my previous postvery frequent failure is due to power supply, so measure voltages on that drive, and check the connector

author: eas
author_rank: Frequent Contributor
timestamp: August 18, 2015, 05:42:02 pm
content: Quote from: suicidaleggroll on August 18, 2015, 03:48:20 pmYup. A hard lesson, but an important one.Quote from: T3sl4co1l on August 18, 2015, 04:24:16 pmBoth SSDs and HDDs fail often enough that you can't trust them to hold the only copy of any data that matters.What do you mean though, you have a RAID5 *pair*? RAID 5 requires at least 3 disks, and should probably have a hot spare, so recovery can begin immediately in the event of a single drive failure. I used to do RAID, but decided that for my use, its better to use the extra disks for independent backups to separate filesystems.As for recovering data directly from the flash. Wear-leveling would make that more complicated, but it shouldn't make it impossible. Isn't the wear leveling information just persisted in the flash itself? It would add another level of indirection to reassembling the original data, but the same is true of recovering data stored on a RAID, or using logical volume management, or even the data on a HDD platter with remapped sectors.

author: TheEnd
author_rank: Contributor
timestamp: August 18, 2015, 05:51:41 pm
content: Remember heating up a board to the solder melting temp in an oven is fine for the top, but gravity still applies on the bottom of the board too!

author: suicidaleggroll
author_rank: Super Contributor
timestamp: August 18, 2015, 06:25:41 pm
content: Quote from: madires on August 18, 2015, 05:05:10 pmI haven't seen that report, but even so it's of little importance to this thread or likely anybody in it. Data center usage is nothing like personal, gaming, small business, or any other usage. You could hit the write limit of an SSD in a matter of weeks if you tried, that doesn't mean everybody's SSD will fail within a month...far from it.Also we need more info - were they comparing failures per 100 units or failures per 100 TB, since if you have to stack up 8 SSDs for each HDD to match the capacity, you're 8x more likely to lose a drive than with just one SSD. Not an issue for an individual, but it might matter for a datacenter that needs to hold PB of information.Of course you would compare consumer grade SSDs to consumer grade HDDs, why would you compare bargain basement consumer SSDs to $1k+ enterprise SAS HDDs?In my experience dating back over 10 years with hundreds of HDDs and ~40 SSDs, consumer grade (almost all Intel) SSDs have a MTBF of somewhere around 1e6 hours, but honestly I've had so few failures (exactly 1, out of over a million hours of run time) that it's hard to put a number on it. Meanwhile the consumer grade HDDs (typically HGST or Western Digital) have a MTBF of around 2-3e5 hours. Somewhere around 3-5x worse than the SSDs. Again though it's hard to put a number on the SSDs since I've only ever lost one (a Crucial M4 that was about a year old at the time).

author: amyk
author_rank: Super Contributor
timestamp: August 18, 2015, 06:37:24 pm
content: K9CHGY8S5M = 3-bit MLC, one of the worst data retention and endurance flash out there (only the 4-bit stuff is worse.) You can probably read out the data using standard commands but without knowledge of the ECC/scrambling used it will be impossible to recover.

author: DimitriP
author_rank: Super Contributor
timestamp: August 18, 2015, 06:45:17 pm
content: Quote from: Ferroto on August 18, 2015, 10:49:43 amDepending on how critical and irreplacable your data is, you may want to send the drive out for recovery to a place like ontrackhttp://www.krollontrack.com/.If the data is not a big deal, yeah it might be a good excuse to "take it apppat"...

author: suicidaleggroll
author_rank: Super Contributor
timestamp: August 18, 2015, 06:50:37 pm
content: Quote from: amyk on August 18, 2015, 06:37:24 pmThis isn't the first I've heard about the Samsung 840 TLC drives kicking the bucket prematurely. Exactly the reason why I won't buy a TLC drive, you're killing reliability to save a few bucks.

author: Jeroen3
author_rank: Super Contributor
timestamp: August 18, 2015, 07:45:55 pm
content: Often you do not need to actually bring the oven temperature up to the melting point. The thermal expansion is often enough to make contact for recovery.That is why the freezer trick also works sometimes.

author: Ferroto
author_rank: Frequent Contributor
timestamp: August 18, 2015, 08:15:30 pm
content: Quote from: DimitriP on August 18, 2015, 06:45:17 pmIt's not that important most of my important stuff is on a 3tb raid 1 array. There's still some arduino sketches and stuff that I would like to get back though.

author: T3sl4co1l
author_rank: Super Contributor
timestamp: August 19, 2015, 04:00:40 am
content: Sorry, RAID1Strangely, I have had almost zero HDD failures over some decades. I have a 30 and a 60GB HDD that had been spinning for at least 10 years, and this despite one having a whining sound for half that time. The only failures I've seen were both mobile: one old laptop drive froze solid and made struggling chattering sounds; another lost track of the MBR (bit rot due to that sector never being refreshed?) but was otherwise in perfect working order.Not that anecdotes count for anything. Perhaps my luck is balancing out yours..Tim

author: Jeroen3
author_rank: Super Contributor
timestamp: August 19, 2015, 06:20:51 pm
content: If the files you want to recover are smaller than a flash block, you "should" be able to find them in a binary dump of the disk. If ntfs compression was off.

author: wraper
author_rank: Unknown
timestamp: August 19, 2015, 06:28:10 pm
content: Considering controller used, this probably is 840 Evo SSD or similar. AFAIK they have 256 bit AES hardware encryption. So even if you move the flash chips to another working PCB, this won't help a tiny bit to recover the data.

author: SL4P
author_rank: Super Contributor
timestamp: August 19, 2015, 06:57:55 pm
content: Once again, it should be pointed out for general reference that RAIDanythingin itself is NOT a backup, it merely reduces downtime.

author: tooki
author_rank: Super Contributor
timestamp: August 19, 2015, 11:07:11 pm
content: Quote from: suicidaleggroll on August 18, 2015, 03:48:20 pm^^ this x 10^9.

author: hendorog
author_rank: Super Contributor
timestamp: August 19, 2015, 11:49:26 pm
content: QuoteAnd actually increases the probability of failure because there are more things to failMany people have horror stories about RAID. It's an additional level of complexity and tends to bite three years down the track when you have forgotten all the little details about setting it up.QuoteAssuming you have a complete bare-metal backupthat you have actually restored from recently and tested the restore.You never really know how hard it will be to restore a backup.Hopefully you get lucky and have no issues, but I'd never assume it will be Easy. There is always something you forget.My current strategy is this:* Time machine backup to external HDDs for my primary laptop <- manual so exposed to human failure and failure of the backup drives* Github ($) for all source code <- exposed to human failure if I don't check stuff in* Spideroak ($) on all PC's for everything important <- exposed to human failure if I don't select something.* Mobile phone pics auto upload to google cloud* Gmail for email <- so fingers crossed they don't drop the ball

author: suicidaleggroll
author_rank: Super Contributor
timestamp: August 20, 2015, 01:25:00 am
content: Quote from: SL4P on August 19, 2015, 06:57:55 pmAbsolutely true. All it takes is a bad power supply failure that takes out all of the equipment in your system and it doesn't matter how much redundancy you have in your array, it's gone.I had a supply do that a while back. The mobo was fried but I hoped the drives were alright. As soon as I plugged one of them into another computer to try to recover the data off of it the drive quite literally lit on fire...

author: suicidaleggroll
author_rank: Super Contributor
timestamp: August 20, 2015, 01:33:45 am
content: Quote from: hendorogYou can't blame the architecture for problems due to lack of note taking...take a freaking screenshot of the configuration page on your management utility and you're done...Quote from: hendorogSorry, I typically operate under the assumption that people use an OS where all of your settings and configuration details can be restored easily without a full metal backup. Reinstall the OS, run a couple of commands to reinstall your programs, copy your home directory off of the backup, and you're done. I forget that Windows doesn't recover so easily....

author: hendorog
author_rank: Super Contributor
timestamp: August 20, 2015, 01:46:57 am
content: QuoteAnd don't forget to backup your screenshotsAnd take screenshots every time you change anything etc...QuoteQuite. I used linux for many years, and I agree with you, it's so much simpler.However I have found in the electronics industry Windows is deeply entrenched.

author: Psi
author_rank: Super Contributor
timestamp: August 20, 2015, 06:24:26 am
content: Don't oven reflow in a fan bake oven unless you have the pcb inside a dish with a lid. Or the air will move components around.And of cause you need to mount it correctly with some metal spacers so its not touching anything

author: tooki
author_rank: Super Contributor
timestamp: August 20, 2015, 09:49:16 am
content: Quote from: SL4P on August 19, 2015, 06:57:55 pmQuoted for truth. RAID protects you -- at most -- from drive failure. (The degree of drive failure tolerance depends on the RAID level. And then there's "RAID" 0, which is actually anti-redundant, in that a single drive loss instantly and irrecoverably results in total loss of the entire array.) RAID cannot and will not do anything to protect against human error, corruption due to software bugs, fire, theft, etc.

author: technix
author_rank: Super Contributor
timestamp: August 20, 2015, 12:46:43 pm
content: Usually you cannot do this even you may be able to JTAG the raw data out. If you have a backup, you will be able to roll back; if not, you will have to kiss the data goodbye.There is nothing wrong with SSD and to me they have roughly the same failure rate as HDDs. Although I am talking about Intel SSDs not Samsung's notoriously buggy TLC NAND Flash, like the one you have here. Next time when you buy a SSD, drop a few (times) more $$$ and get one from a reputable brand like Intel or Kingston, el cheapo will bite you.HDD with large capacities are pretty cheap now. My NAS box have a WD Green 6TB in it holding one of my two backups, and the other is held in a RAID-10 array consists of 6 WD Green 2TB drives. The RAID-10 will allow me to lose up to three drives before losing the array, and the 6 drives are all bought at different times so they will not fail from age at the same time.

author: SeanB
author_rank: Super Contributor
timestamp: August 20, 2015, 08:21:20 pm
content: I will also add never buy the latest drive with the largest capacity. Buy the model that has been out for a few months with lower capacity, as there you at least are getting a product line which hopefully has been field tested for reliability. Cheaper as well, and buy a few of each drive and mix them in use so the same model does not have all the copies of the data.Just had an external caddy PSU kill 2 500G drives........ I had them in a storage case and wanted to see if they were still working, and after 10 minutes it killed the one. Now to go buy some new drives from the local supplier to redo the data from the other ones. Only one drive was new, the other came from a DVR system which suffered a close lightning strike which popped the cameras and the DVR power supplies, but left the drive working as it was floating in the unearthed case. New one has everything earth bonded, and it has survived the storms so far.