Would chip-off/swapping the NAND to a different board work for the Samsung PM991?

Can you show us a photo of the SSD?

Samsung's photo of the PM991a suggests that this is an SSD-on-a-chip:

https://semiconductor.samsung.com/ssd/pc-ssd/pm991-pm991a/

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Yeah it’s NVME SSD with BGA Nand

The photo is unintelligible, but it is in fact a single-chip SSD. That main chip incorporates both NAND and controller, and possibly SDRAM. Transferring this chip to another PCB would achieve nothing, unless there was a fault in one of the external power chips.

If you have a multimeter, and a clearer photo, I could help you identify and measure the power supply test points.

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A backup a day keeps DR away.

Apologies, don’t have the SSD with me at the moment, only got these photos.

Can you explain a little bit as to why a single-chip SSD doesn’t allow swapping PCBS? Sorry for the questions, just new to this stuff and wanting to learn

For such cases the easiest way is fix PCB (of course if problem is not with FW - mostly it is). Swap is bad idea.

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It would (should) be much easier and safer to repair the PCB, if the problem is external to the IC.

"AtBQW" is an e-fuse. It can be bypassed if it is faulty.

"PD5Q" are step-down converters which can be easily sourced from Mouser, Digikey, Farnell, RS Components, etc.

"UM" is a reset supervisor which can also be easily sourced.

Chip-off in this case is for those people who have zero troubleshooting skills, and there are plenty of those.

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A backup a day keeps DR away.

Chip-off's not been an option for ssd's for a while, that pesky thing called encryption. Moving the nand is also problematic in terms of serialisation, and in your case it's an all in one so unless there's a pcb fault it would be pointless. What's the problem with it and has somewhere told you it needs chip off? As per Arvika post anything samsung is usually firmware and unrecoverable.

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