HDD GURU FORUMS

Hi Guys,

Hope you can help me!

My main desktop PC has two Samsung SSD 840 PRO 256GB (MZ7PD256) running in RAID 0. Today I had a power failure whilst the computer was on and when the power was restored, the computer could no longer boot. Checking the BIOS, I noticed that only one of the 840 PRO's was being detected. I've removed the failed SSD from the computer and tested it with a USB to SATA adapter on another computer but it's still not being detected.

Apart from taking the SSD to a data recovery centre, do I have any other options I could try to get it working again. Is it possible that the firmware could have become corrupt and I could try flashing it similar to the technique in this post -https://forums.tomshardware.com/threads/samsung-850-pro-ssd-corrupted-firmware-fix-read-first.2193040/ ?

Thanks in advance for any assistance you can offer.

Cheers

If you wanna try that method, save byte-to-byte image first from donor ssd, just in case.

DR-Kiev wrote:If you wanna try that method, save byte-to-byte image first from donor ssd, just in case.

Thanks for your reply, DR-Kiev however, I wasn't able to get it to take the firmware when I hot swapped over to the faulty SSD.

Is there any easy way to determine if the SSD is powering on? I'm starting to think that some of the components might have been damaged either when the power went out or came back on. I assume that if I measure 5v around the controller IC then that's going to be the best way of telling?

FWIW, the voltage test points for the 840 Evo are in @sourcerer's "Missing Manual":

http://www2.futureware.at/~philipp/ssd/TheMissingManual.pdf

If you need specific help with your Pro SSD, please provide detailed photos of both sides of the PCB.

fzabkar wrote:FWIW, the voltage test points for the 840 Evo are in @sourcerer's "Missing Manual":

http://www2.futureware.at/~philipp/ssd/TheMissingManual.pdf

If you need specific help with your Pro SSD, please provide detailed photos of both sides of the PCB.

Thank you, fzabkar. I appreciate any advice you can suggest. Photos of both sides of the PCB are below.

The voltage test points are marked in the attachments.

Hello,

i have SM841 - same as 840pro - can't enter Safe Mode to read out with PC3000, and it stays BSY when entering normal Mode

so i measured the voltages named like in picture, and there are some with 0V - is it correct, or is there another pic where i can see what voltages there should be

V1 = 1,93
V2 = 0
V3 = 2,95
V4 = 1,84
V5 = 0
V6 = 1,16
V7 = 1,05
V8 = 0

Check the 3 ENable pins of the RT9991.

https://www.richtek.com/assets/product_file/RT9991/DS9991-02.pdf

I don't have a datasheet for the LM10515SQ, so I don't know what is going on there.

EN1 0V
EN2+3 5V

Either the V2 output is shorted to ground, or the RT9991 converter is faulty.

I would also test for shorts at V5 and V8.

hm - it looks like no shorts on all 3 0V voltges. always >30kOhm - so maybe it's really dead - ill check some things - maybe i'll find something out thx for now.

I would replace RT9991. Perhaps V5 and V8 are asleep, and V2 needs to come up before they can be woken up??

fzabkar wrote:I would replace RT9991. Perhaps V5 and V8 are asleep, and V2 needs to come up before they can be woken up??

Changed RT9991 - and it's online - thx