RPI3B+ does not reboot

[Trev]

Wis Macomson wrote on 03/07/2018 00:58:
> Can you disconnect the serial TX data (data to the RPi) and try the reboots?
> 
> It may be that this signal is partially powering the processor through the input ESD 
> protection diode, leading to very awkward internal states. This has been observed on
> the Rock64 (RK3328 SoC) and Rockpro64 (RK3399).
> 
> If you can just break the TX connection, you'll be able to see the boot messages.

I removed Tx and left Rx and Gnd connected but on the first reboot 
attempt I still suffered:

All buffers synced.
Uptime: 11h34m59s
Rebooting...
cpu_reset failed