On Fri, 17 Jul 2020 22:06:08 +0200, in gmane.comp.hardware.beagleboard.user
Reiner Buehl <
reiner.buehl-Re5J...@public.gmane.org> wrote:
>The power supply is on all the time. I just switch the 5V on/off with a
>switch. After switching on, the power LED is not on. If I then press the
>Power button, the power LED switches on and the board boots.
So you aren't switching the power supply, but somehow are toggling some
sort of inline switch on the power lead?
<shudder>
Switch bounce could be scaring (if not scarring) the PMIC -- if it sees
a series of up/down transitions from the bounce (use a storage tube or
digital oscilloscope with probe and ground held to the end&side of the
barrel connector, and flip the switch -- if you see ___|-|_|-|_|---- at the
start of the sweep, you have switch bounce). Pushing the power button is
taking place after the voltage stabilized. Possibly fitting a capacitor
between the power leads (value TBD -- large enough to smooth out bounce,
but small enough to not cause the opposite problem of a too slow
transition) would help.
--
Dennis L Bieber