For $29/mo, we provide access to advanced level technicians who will answer your questions on any Macbook board related matter to the best of their knowledge promptly & walk you through how to solve your problem so you can deliver a working board to your customer.
This was not liquid-damaged. Just stopped recognizing SSD's. Tried a bunch. No change. Any idea what would cause something like this? Not seeing anything off yet.
First start with USB OSX and check if Disk Utility sees the SSD at least.
Just in case is a problem with APFS and BIOS; is better to discard that first.
Next, post U3740 voltages.
Be sure U8070 and L3700 are good.
Thanks, that got me there. Had some crud on the back of the connector on pin 47 that the ultrasonic didn't get. Wasn't getting voltage because of that. Working now.