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Samsung Evo 840 SSD Faults – Beware

By |2026-10-07T07:07:01+01:005 July 2016|Data Clinic Ltd|Comments Off on Samsung Evo 840 SSD Faults – Beware

Data Recovery from Samsung EVO SSDs

Over the last year our data recovery engineers have encountered an alarming number of these popular SSD’s from Samsung. During this time, we have been able to research and develop our capabilities to allow for many of the cases we have received to be recovered.

Samsung EVO SSD | Data Clinic LtdHowever, the underlying problem with these Samsung Evo SSD’s is simple – bad TLC NAND chips. As I’m sure most SSD users are aware, the data stored on SSD’s is chip based (rather than platter based as used in HDD technology), with many chips concatenated using various algorithms controlled by the unit to create a large storage volume – think of many flash drives combined into one and you won’t be far wrong.

Many of the Samsung Evo drives pre 3DNAND (Samsung’s new non-TLC based chip) suffer from slow reading/writing or not being recognised by the host computer. In 90% of the time this is caused by cell degradation due to the poor quality NAND chips used. Cells within the NAND chip over time degrade with the voltage inside dissipating or the cell becomes weak and the drive requires more reading time by invoking ECC error correction which causes the read delays significantly slowing down the 500MB’s rated SSD.

Six months ago our technicians instigated a test, we purchased a Samsung Pro Evo 840 brand new and filled is with useless but working data. This was then left unused for approx. 5 months, no reading/writing to the drive was completed nor was power supplied. When we later attached this up to our test equipment the partition and large amounts of the drive were unreadable proving if left long enough the voltage inside the cells dissipates and data is lost. Samsung has since released a firmware update for the effected models which when power is provided to the drive will read and write cells to keep them ‘fresh’, this isn’t however useful if the drive is left for a period of time unpowered, certainly not a fix for very poor NAND chips.

Thankfully as mentioned above Samsung have rectified newer models by using newer NAND technology, however be aware that if you have an older Evo SSD utilising TLC based NAND you may encounter issues and significant data loss. Data Clinic have designed specialist equipment and processes to gain access to Samsung Pro Evo SSD’s even if they are damaged and can in most cases attain a very good recovery if the chips are not too badly degraded.

A Case Study

Take the following case which arrived at our main lab, whilst not a Evo 840 this SSD still uses the same controller and NAND storage chips.Samsung-PM851-MZ-7TE2560 | Data Clinic Ltd

Model: Samsung PM851 MZ-7TE2560
Form Factor: 2.5″
Capacity: 265GB
Symptoms: Not recognised by the PC and remained BSY (Busy) when attached to our diagnostic tools.

In order to communicate with this SSD our technicians were required to place the drive into safe mode. Safe mode on this model was instigated by shorting 2 pins on the PCB. Once safe mode was attained we then uploaded microcode to the RAM in order to simulate the normal drive initiation process, this allowed direct physical access to the NAND storage and allowed for basic read testing too be conducted. Once completed it was clear that although each chip was reading, 2 were suffering from read errors throughout.

After some further firmware fixes from our technicians we were able to gain logical access to the drive and begin a clone of the device over to a new stable HDD. After approximately a day our tools had produced the best possible copy of the failed SSD and from approx. 512,000,000 sectors we were unable to read 5,000,000 – these were the degraded cells. We then provided a full file list of both the good and bad files to our client who was over the moon with the result and completed the recovery case.

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Will Kirkwood
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fully recovered data from corrupted drive and assisted in return media issues
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Incredible job. They managed to recover ALL the data which I was told cannot be recovered by other specialists. Saved my business from months of tedious recovery work, highly recommend.
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My phone was water damaged, I had some backup, but I was worried that I'd lost a year's worth of holiday photos forever. Drying the phone out didn't work. I searched the internet, there were a number of data recovery choices, I read reviews and was a bit skeptical that I'd ever recover the pics, or that I'd be fleeced for the 'full' amount to get anything back. I chose data clinic as they had a tiered service and I could in theory cut my loses if it got too expensive. They recovered on the first tier, so I paid the initial amount only (I sent them my own drive). They sent it back with the broken phone today. Everything is recovered. I couldn't be happier. Now I have automatic backups and cloud storage.
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So happy I sent my phone here for data recovery! I looked at a LOT of different options to save my phone's data, and ended up taking the plunge with Data Clinic. They were very clear about price and recovery, and I knew this would be a tough recovery. Very happy to have got my data back and appreciate their help throughout the process
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Excellent service, quick turn around and plenty of comms keeping me informed of progress. HDD had failed and all fully recovered. Highly recommend Chris at Data Clinic.
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After trying local phone shops who were unable to either revive my seawater damaged phone or recover the data, I found DataClinic. The process was clear in the pricing, the levels of recovery and the timeframe. Always available on the phone to review contract terms. After a week, they managed to recover the data which included precious photos, videos and also WhatsApp backups. Not only this, they revived my phone which I was told may not happen due to the saltwater damage! I am more than pleased with the outcome. They returned my phone back along with a USB drive of the data. They did forget my simcard tray but a non-issue in light of the service provided. Thank you!!
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The Data Clinic team have been recovering data in the UK since 2002. All recovery work is carried out in our Bury, Manchester lab, on hard drives, SSDs, RAID servers, phones and cryptocurrency wallets. For single hard drives we work on a No Data, No Fee basis, and we can arrange collection from anywhere in the UK. Trusted by businesses and individuals nationwide. Call us on 0800 151 2207 for a free quote.

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