I am trying to create an in-car (headrest) entertainment system using the Pi 3B with 7" screen using OSMC, when OSMC is shutdown it does not fully power off the screen, I can detect the shutdown using one of the GPIO pins, so far so good, the problem arises when I boot using a 5A 5V supply (this is a 12v to 5v DC to DC converter) via the micro USB port, it acts like the micro USB cable I have is throttling the current although it is supposed to be a 2A cable, when I plug in the official RPi power supply it boots up as expected. I have tried multiple different DC to DC converters because I thought it may have been those causing the restriction but that's not the case.
From what I have read the options for powering the Pi and 7" screen
- Micro USB (best option with protection)
- Std USB port (not ideal and has its own problems and a 0.5A restriction)
- GPIO pins (again not ideal due to circumventing protection and current limit)
My question is how do I get the required current into the micro USB if all the cables i am finding throttle the required current? I suppose I can always cut the cable off an official power supply as that has a large current capacity but that seems a bit destructive, has anyone else come across this problem? Soldering directly to the pins is a bit tricky?
Any feedback appreciated Regards Simon