What type of uHDMI to HDMI connection (cable) are you using?After running the RPi (3 an4) in headless mode for many years, I decided to install Raspberry Pi OS w/desktop on a RPi 4b. Normally I would physically pull the USB power cable after 'sudo poweroff'. With the new desktop install, there is an micro-hdmi connection for video that also supplies 5v power to the pi (the leds come on when only hdmi is connected)
This extra hdmi connection makes poweroff/on handling a bit tricky - potentially causing static damage and 5v conflicts between the hdml 5v supply and the usb supply. I can see where a switched powerstrip would help but how does one control the hdmi 5v to the pi? Or am I over thinking the potential for damaging the pi?
Eg. are any adapters or HDMI switches in use too? A direct connection to a display/monitor/TV does not normally "backfeed" 5V - the "5V connection" is meant to power the display's circuitry that provides EDID info. back to the Pi etc. However some HDMI switches do not isolate said 5V (inputs) from each other, eg. this one https://www.cpmspectrepi.uk/raspberry_p ... tcher.html
as opposed to this one, which was O.K. https://www.cpmspectrepi.uk/raspberry_p ... cher2.html
However the current available from such a feed is usually not enough to fully power-up a Pi, but may "upset" shutdown rather than cause damage.
Trev.
Statistics: Posted by FTrevorGowen — Wed Jul 24, 2024 6:51 pm