Keyboard, Trackpad, and USB unresponsive on ANSI PBP

[belfastraven]

I've had some time to inspect it a little bit more. I'm used to troubleshooting issues with ~40-year old computers but I'm not very savvy with modern equipment.

I decided to test the voltages on the GL850G (Genesys USB2.0 Hub) chip based on the datasheet i found here https://www.kean.com.au/oshw/WR703N/GL85...201.07.pdf and found that both pin 23 (V5) and pin 24 (V3) are at 3.3V. I don't know if that's how it is supposed to be or not for this chip as I expected pin 23 to be outputting 5V but I could very well just be misunderstanding the datasheet. Testing all the USB ports though shows that none of them are receiving any power whatsoever. This makes me think that there might be some component on the board  that has failed that may be power related and not USB related.

A step I have thought about trying next is building a frankenstein cable to draw power from a separate device's USB port and plugging into the PBP to see if it works with external power. I don't know if that could cause any issues or not.

Does anybody know what other components I could test? I've had a look at the PBP mainboard schematic but it's far above my skill level to use for troubleshooting purposes unfortunately.

If you don't have a serial cable,  (which would allow you to see u-boot messages which would give some insight into what is happening),  the one thing I would suggest before contacting support is to remove the emmc and throw the emmc switch  so that you are positive you are not
booting from it.  If the same problem occurs,. I think you really need to contact support.  (Sorry that I forgot that USB would need to work to use wired ethernet...)      I think its strange that none of the USB ports are working,  since they are on different hubs,  and seem to be using different regulators, etc.   Things llike that can be caused by software problems, though.  That is why I am wondering about the emmc.