I have tried 3 motherboards so far, it will boot to BIOS if I press ESC when I first turn on the laptop. BIOS reads 6GB RAM. There is only one removable RAM slot and it currently has a 4GB stick in it of DDR3. Initially I thought that the embedded RAM was faulty so ordered a replacement board for it. It has the same problem. Even tried one more board, same problem. Boots back and forth between the ASUS board splash screen and the Windows 8/10 logo. Then it says it will try to repair but ends up going back to the ASUS screen to the Windows 8/10 logo screen. It keeps doing that until I shut it down. The obvious things that all 3 boards had in common were the CMOS battery and the 4GB RAM stick. Ideas?