WD SN520 Nvme

[n3dv3d]

Hi everyone, I have this SSD that is not being detected. After trying a few measurements, there doesn't seem to be any short circuits. Does anyone have any suggestions? Are there any pins to try to put it in safe mode?

Thanks in advance

Attachments

[fzabkar]

FWIW, some SanDisk SSDs use the NAND Ready/Busy* pin as the ROM mode jumper.

[fzabkar]

The tiny BGA device near the ACT9045VM333 PMIC is a load switch. Check the input and output voltages.

NCP451FCT2G, ON Semiconductor, load switch, 0.75V – 5.5Vin, 3A, 13mOhm Rdson, marking 451, WLCSP6

NCP451AFCT2G, Onsemi, Load Switch, 3A, 0.75V - 5.5Vin, marking 51A, WLCSP6

https://www.onsemi.com/download/data-sheet/pdf/ncp451-d.pdf

[n3dv3d]

Hi,

thanks for your reply.
It's not easy to take the measurement, but it appears to be input 0.110V output 3.3V.

Thanks

[Lardman]

It's not easy to take the measurement, but it appears to be input 0.110V output 3.3V.

Are you sure you haven't reversed vin and vout

[n3dv3d]

It's not easy to take the measurement, but it appears to be input 0.110V output 3.3V.

Are you sure you haven't reversed vin and vout

sound strange to me too but:

Attachments

tempsnip.png (16.85 KiB) Viewed 5163 times

[Lardman]

Where are you taking the measurements - can you measure resistance to ground pins c1 and c2.

[n3dv3d]

Where are you taking the measurements - can you measure resistance to ground pins c1 and c2.

I measured voltage between A1<->GND and A2<->GND.
Resistence C1<->C2 seems to be about 1,9Mohm.

Thanks

[Lardman]

What was their resistance to ground not to each other, it will confirm your chip orientation.

[fzabkar]

I'm basing my identification of the load switch on other photos. Have I correctly identified the marking?

[fzabkar]

The demo board on page 8 of the datasheet shows that the pins are reversed. It looks like the top view is actually a bottom view.

This demo PCB seems to confirm the error:

https://media.digikey.com/Photos/On%20Semi%20Photos/MFG_NCP451FCT2GEVB.jpg

Can you measure any voltages at the inductors and capacitors surrounding the ACT9045VM333 PMIC? If not, check that the output of the load switch is not shorted to ground. Also confirm that there are no shorts to ground around the PMIC.

If all is good, then you should be able to bridge Vin and Vout at the load switch.


Edit: Confirm that the load switch is being enabled. There may be a missing control input from the DevSleep pin on the interface (DevSleep should be 0V).