Is it Soc I/O problem? it can't connect to slow speed usb

I’m trying to repair a nintendo switch. (V1 Erista)

There was a usb connector damage.

I changed P13usb, M92t36, USB Connector.

OFW is good.
Charging is good.

It can’t to inject the payload by Rcm Loader

when I connected it to the PC, it was “NO RCM” on the TegraRcmGUI.

I saw a post saying that it could be a Soc I/O.

How can I diagnose it conclusively?

Maybe check resistance and diode readings on the d+ and d- lines.

thanks for your reply.

I checked resistance and diode reading . ( red probe to GND. Black Probe to point)

D- : 0.484~0.507 or 0.722 (76.6 k ohm)
D+ : 2.116 vdc (29.23 k ohm)

I got 0.8 in diode mode and 2.5M… on both lines. I dont know what that means to be honest, but yeah, quite possibly SoC damage on those lines.

is this photo your actual board?

if you can boot into HOS just fine, I’d imagine your SoC is just fine? If that is indeed your board in the pic, third pin from left on the USB port looks a little light on solder.

just to be clear, you are using a jig or unplugging the eMMC to force RCM mode?

Not always the case unfortunately, often times a whole “functional block” of the SoC is wiped out in cases like this.

oh wow, didn’t know that, my caveman logic would just assume it would stop the boot entirely. Thanks!

your half right, in cases where USB/M92 (mangled pins and the like) occur, it’s a coin flip whether it will take out the USB “functional block” out or the SoC as a whole. What I can say is in these circumstances, if the diodes are populated on the board, the chances of either scenario are marginally less likely.

To the OP, your readings do seem a little on the low side (if I remember right) , maybe worth pulling the diode/s and seeing if your readings increase to normal (don’t reconnect power with the diodes out of circuit until you verify no other issues)

interesting, I will have to do some more reading on the architecture of this chip then. I have to admit I barely have knowledge on it minus a few basic elements. Thanks again for the insight!

Yes, It’s a picture that I took myself.

I checked all soldering point. there is no problem.

when I use the jig, it is rcm mode. (just black screen)
but, do not allow usb connection.

Good stuff ::+1:

So the filter for me always shows open line in diode mode when 5v charging rcm mode don’t work.

I would personally remove both diode arrays. I think they say dug on.

I might be wrong on this so someone with more knowledge which me better, but I think the MOSFET at the top of the board above m92 might be connected.
(I haven’t tested this, I’ve just read it somewhere.)