820-00165 Not Detecting SSD


New member
Firstly, I think it's important to mention I have very limited board repair knowledge. I've done a few basic repairs, but never something as involved as this

I'm working on an 820-00165 board that will not detect an SSD. Used a known good SSD and it doesn't show up in boot menu or DU (Internet recovery)

PP3V3_S0SW_SSD_FLT is 3.3v
SSD_PWR_EN is 2.9V (pin 1 of U3711)

No corrosion around SSD connector, all looks good there. Originally the board was an intermittent boot, but corrosion was cleaned off of a few components in the PPBUS circuit and that issue seems to have been resolved

Not sure if this is relevant, but the mac will not boot into internet recovery using the key combo, only through the boot menu

Thank you!


Staff member
First of all, welcome to the forum!

Compare with good board if possible.

Be sure R3701/2 and their traces are good.
Also check the traces to all series caps, C3710-17.


New member
Thank you!

SSD_BOOT_R is 0v, but the only resistor on that line (R3701) is "No Stuff". Compared to donor board, it's not there either. I don't have a functional board to compare to unfortunately

SSD_SR_EN_L shows 2.8v. Resistor shows 100k on schematic, but measures 60k. Same on donor board though

R3702 and series caps all test good


New member
All rails going IN to the connector measure .432 on both boards. I used the same SSD and another working 00165 board

The rails leaving the connector are .550 on the bad board, but .385 on the good board (red probe on ground for both)


New member
Good board is .392 on all

Bad board is .430 on C3710-C3713
C3714 is .461
C3715 is .441
C3716 is .837
C3717 is .412


New member
I'm thinking the same, looks like I have a new donor board now lol

Thanks for your help, I appreciate it!