820-3476 not seeing SSD

[dr. moast]

Hi,

we have a 820-3476 here which is not seeing the SSD. No repair or water damage history, no visible damage to the connector. All pins except GND measure resistance to ground.

SSD_PWR_EN, PP3V3_S0, SSD_RESET_CONN_L, SSD_CLKREQ_CONN_L, SSD_PCI_SEL_L are 3.4V
Flashed BIOS, replaced SMC

Of course tested with known-good SSD.

Last thing on my mind is the PCH, or am I missing something?

 

[G.Beard]

Boot from a USB into the installer with the SSD plugged in and check in Disk utility. does it see a volume or drive?

 

[dr. moast]

Yeah, tried that of course. Isn't seen at all. Sorry for not mentioning.

 

[dukefawks]

Firstly put back the original BIOS.
Check all caps in the data lines C3710 and up. Diode mode on one side and continuity to the connector on the other side. Also inspect for damage.

 

[Bad Apple]

I had one that wasn't recognizing internal SSD same as OP. I followed Dukes instruction and focused on Capacitors C3710 and up. I couldn't figure out how to do a continuity test without an extra set of arms or soldering a jumper wire to each Cap so I re-flowed them and it worked. I never would have suspected them as they were as clean as the rest of the board, it never had a Liquid spill but it was overheating badly when I replaced the display and did a thermal a few weeks earlier.