Can't get 11.0-RELEASE to boot on Banana PI M3

[Hal Murray]

ian at freebsd.org said:
> And why exactly is two sources of +5v a problem (not that I said I was doing
> that, but I have at times done that, and it works just fine)? 

That connects 2 regulated power supplies together.  They are unlikely to be 
trying to regulate to the exact same voltage.  If the connection is solid, 
one power supply would probably turn off and let the other do all the work.  
If the connection is crappy (long thin wires), then they will share the load 
with the size of each share depending on the voltage from that supply and the 
resistance of the wires/connectors between the supply and the load.

Things get interesting if you turn one supply off.  The other supply will try 
to power everything on that side.  That may look like a short circuit.  USB 
sources are supposed to handle short circuits but I wouldn't be surprised if 
low cost gear got hot or let the smoke out.  Power flowing the wrong way 
isn't something designers think of when they are trying to save pennies.


-- 
These are my opinions.  I hate spam.