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| Lexar NM790/MAP1602A- need shorting point for ROM mode. http://forum.hddguru.com/viewtopic.php?f=10&t=46268 |
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| Author: | pikus_09 [ September 1st, 2026, 18:00 ] | ||
| Post subject: | Lexar NM790/MAP1602A- need shorting point for ROM mode. | ||
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:
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| Author: | fzabkar [ September 1st, 2026, 18:21 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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. |
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| Author: | pikus_09 [ September 1st, 2026, 18:35 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
This is marked ic 8102. A try make clearly from my phone but all the time picture is not clear. |
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| Author: | fzabkar [ September 1st, 2026, 18:41 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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. |
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| Author: | pikus_09 [ September 1st, 2026, 19:06 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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 |
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| Author: | fzabkar [ September 1st, 2026, 19:30 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
I thought it may be a Silergy IC, but EAExyz is an LDO regulator. I tried FAExyz, but couldn't find anything. |
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| Author: | pikus_09 [ September 1st, 2026, 19:52 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
Yeah, nice. The pcb revision is PCM0002A1727. |
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| Author: | fzabkar [ September 1st, 2026, 20:01 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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. |
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| Author: | pikus_09 [ September 2nd, 2026, 3:58 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
I try, find any datasheet for this IC, and can't find any info. |
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| Author: | fzabkar [ September 2nd, 2026, 4:10 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
pikus_09 wrote: 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. |
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| Author: | pikus_09 [ September 2nd, 2026, 4:35 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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!? |
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| Author: | fzabkar [ September 2nd, 2026, 7:33 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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 |
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| Author: | pikus_09 [ September 2nd, 2026, 8:35 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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. |
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| Author: | fzabkar [ September 2nd, 2026, 8:40 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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. |
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| Author: | huibooo [ September 29th, 2026, 19:52 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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. |
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| Author: | pikus_09 [ September 30th, 2026, 6:45 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
huibooo wrote: Thank you both for this thread. can you paint which are pins?
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. |
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| Author: | huibooo [ September 30th, 2026, 12:14 ] | ||
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. | ||
pikus_09 wrote: huibooo wrote: Thank you both for this thread. can you paint which are pins?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. 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.
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| Author: | fzabkar [ September 30th, 2026, 13:28 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
@huibooo, did you locate the shorting points by trial and error, or did you use a reasoned approach? |
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| Author: | huibooo [ October 1st, 2026, 12:58 ] |
| Post subject: | Re: Lexar NM790/MAP1602A- need shorting point for ROM mode. |
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. |
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