Lexar NM790/MAP1602A- need shorting point for ROM mode.

[pikus_09]

Hi hello. Need shorting points to enter safemode on this board.
Details:
Main Cpu MAP1602A Maxio
Nands: 2x Longsys YMTC 232L
Interface nvme.
Here is picture:

Attachments

Lexar nm790.

[fzabkar]

This SSD looks similar:

https://www.igorslab.de/wp-content/uploads/2025/09/SSD-Naked.jpg

There is an SOT23-5 IC to the right of the Maxio controller. I suspect that it provides the VCC supply for the NAND flash. If so, then you could short its enable pin to ground. This will turn off the NAND supply and cause the controller to panic.

If you want to try this, show me a clearer photo of that IC.

[pikus_09]

This is marked ic 8102.
A try make clearly from my phone but all the time picture is not clear.

[fzabkar]

https://www.m3tekic.com/filedown.php?file=MT8102_PDS_R0.15_20211209-web.pdf&site=dXBsb2FkLzIwMjIvMDIvMjAyMjAyMTYxNzU4MzYyODIucGRm

If there is a pullup resistor between the EN pin and VIN, then shorting EN to ground should disable the IC. You could short pins 1 and 2 with a DMM probe tip.

[pikus_09]

I try, and nothing, can't detect drive, nothing. This IC is 1.8V for maxio chip, but for nands is PMIC
Marking code
EAEHcH or EAERcH

[fzabkar]

I thought it may be a Silergy IC, but EAExyz is an LDO regulator. I tried FAExyz, but couldn't find anything.

[pikus_09]

Yeah, nice. The pcb revision is PCM0002A1727.

[fzabkar]

It is FAE:

https://www.comptoir-hardware.com/images/stories/articles/stockage/ssd/lexar/nm790/nm790_face_aoilp.jpg

You could at least determine which test points are connected to ground or the supply rails.

[pikus_09]

I try, find any datasheet for this IC, and can't find any info.

[fzabkar]

I try, find any datasheet for this IC, and can't find any info.

I normally search for Silergy datasheets as follows:

https://www.google.com/search?q=filetype%3Adoc+OR+filetype%3Apdf+%22absolute+maximum%22+FAExyz+Silergy

Your IC may be a special part that is not available in the retail channel.

[pikus_09]

It would be SY8686K Marking FAExyz but i never seen any datasheet for this IC.
What can i do, to force ROM on this board!?

[fzabkar]

SY8686K, Silergy, High Efficiency and High Integration PMIC for SSD System, 3 bucks + 2 LDOs, marking FAExyz, CSP2.42×2.82-36:

https://us1.silergy.com/zh/download/downloadFile?id=6348&type=product&ftype=note

[pikus_09]

Yeah, Great, but as you can see, PMIC supplied SOC in my case SOC is Maxio so if i disable power for SOC this I won't be able to enter ROM mode.

[fzabkar]

The trick to enter ROM/safe mode (or ERRMOD) in some Samsung SSDs is to short the I2C clock and data pins. You might try to determine if the I2C pins are present at the test points.

[huibooo]

Thank you both for this thread.

I found the shorting points needed to put the SSD into loader mode: short the two test pads directly above the screw mounting hole during power-on. In the first picture in this thread, these are the two lowest pads (of the 12) on the right side.

[pikus_09]

Thank you both for this thread.

I found the shorting points needed to put the SSD into loader mode: short the two test pads directly above the screw mounting hole during power-on. In the first picture in this thread, these are the two lowest pads (of the 12) on the right side.

can you paint which are pins?

[huibooo]

Thank you both for this thread.

I found the shorting points needed to put the SSD into loader mode: short the two test pads directly above the screw mounting hole during power-on. In the first picture in this thread, these are the two lowest pads (of the 12) on the right side.

can you paint which are pins?

My SSD is a "Lexar 2TB NM790 M.2 2280 PCIe Gen4x4 NVMe SSD". It looks quite the same, as in your picture, but I am not 100 percent sure.

Attachments

Lowest two pads above the screw mounting hole.

[fzabkar]

@huibooo, did you locate the shorting points by trial and error, or did you use a reasoned approach?

[huibooo]

I know only very little of Hardware. I tried to find the shorting points with the help of an AI Assistant and measuring the pads with a multimeter, but in the end I trialed a bit and then found the pins. I then got me some mass production tools from chinese websites (you gotta pay in chinese currency) and a external M.2 NVMe via USB enclosure to use them. But in the end I could not restore my drive to a working state, as the "Jump to system" after the R/W Test did not work. I've spent some 15+ hours trying to get the drive back to live, but to no avail. I wish you better luck

If you want I can dump a generated summary of my AI assistance of what I tried, but I don't want to clutter the thread here. I think the shorting points are the only real help I can give you, as the rest sadly did not work.