I've been tinkering on Acer A715-43g that had boot issues. Voltage rails are present and keyboard LED lights turns on when power is pressed, but black screen and will not continue to BIOS, I also tried connecting to external diaplay and no activity either. I need to do power cycle at least 10 times to boot the laptop and OS will load. I already changed RAM, CMOS battery and SSD. Can you suggest something I need to look or test next?